<PAGE>   1


                                                                  EXHIBIT 10.24

                  FINANCIAL ADVISORY AND CONSULTING AGREEMENT


         This agreement ("Agreement") is made and entered into this 1st day of
April, 1999, between BioShield Technologies, Inc., a Georgia corporation (the
"Company"), and Grayson Financial, LLC (the "Consultant").

         In consideration of and for the mutual promises and covenants
contained herein, and for other good and valuable consideration, the receipt of
which is hereby acknowledged, the parties hereto agree as follows:

         1.       Purpose. The Company hereby retains the Consultant on a
non-exclusive basis during the term specified to render consulting advice to
the Company as the Company may reasonably request relating to financial and
similar matters, upon the terms and conditions as set forth herein.

         2.       Term and Compensation. This Agreement shall be effective for a
period of three months commencing on the date first written above (the
"Engagement Period"). During the Engagement Period, the Company shall pay the
Consultant a monthly fee payable in arrears of $5000 per month (the "Monthly
Fee"). At the end of the Engagement Period, the Company may determine in its
sole discretion to award to Consultant as additional compensation , a warrant
to purchase up to 160,000 shares of common stock of the Company (the
"Warrant"). The Warrant if and when issued shall be exercisable for a period of
five years at an exercise price of $5.00 per share, subject to proportional
adjustment in the event of a stock split.

         3.       Duties of Consultant. During the term of this Agreement, the
Consultant will provide the Company with such regular and customary
non-exclusive consulting advice as is reasonably requested by the Company,
provided that the Consultant shall not be required to undertake duties not
reasonable within the scope of the consulting advisory services contemplated by
this Agreement. In performance of these duties, the Consultant shall provide
the Company with the benefits of its best judgment and efforts. It is
understood and acknowledged by the parties that the value of the Consultant's
advice is not measurable in any quantitative manner, and that the Consultant
shall not be obligated to spend any specific amount of time doing so. The
Consultant's duties may at the direction of the Company include, but not
necessarily be limited to on a non-exclusive basis:

         A.       Providing sponsorship and exposure in connection with the
dissemination of corporate information regarding the Company to the investment
community at large.

         B.       Assisting in the Company's financial public relations, 
including discussions between the Company and the financial community.

         C.       Advice regarding the financial structure of the Company and 
its divisions or subsidiaries or any programs and projects, as such issues
relate to the public market for the Company's equity securities.

<PAGE>   2

         D.       Rendering advice with respect to any acquisition program of 
the Company, as such program relates to the public market for the Company's
equity securities.

         E.       Rendering advice regarding the public market for the Company's
securities and the timing and structure of any future public offering of the
Company's equity securities.

         It is expressly understood that no actual or express authority on
behalf of the Company is granted by the Company hereunder to Consultant.

         4.       Relationships with others. The Company acknowledges that the
Consultant or its affiliates is in the business of providing, among other
things, financial service and consulting advice (of all types contemplated by
this Agreement) to others. Nothing herein contained shall be construed to limit
or restrict the Consultant in conducting such business with respect to others,
or in rendering such advise to others. In connection with the rendering of
services hereunder, Consultant has been or will be furnished with confidential
information concerning the Company including, but not limited to, financial
statements and information, cost and expense data, production data, trade
secrets, marketing and customer data, and such other information not generally
obtained from public or published information or trade sources. Such
information shall be deemed "Confidential Material" and, except as specifically
provided herein, shall not be disclosed by Consultant or its employees or
agents without prior written consent of the Company. In the event Consultant is
required by applicable law or legal process to disclose any of the Confidential
Material, it is agreed that Consultant will deliver to the Company immediate
notice of such requirement prior to disclosure of same to permit the Company to
seek an appropriate protective order and/or waive compliance of this provision.
If, in the absence of a protective order or receipt of written waiver,
Consultant is nonetheless, in the reasonable written opinion of Consultant's
counsel, compelled to disclose any Confidential Material, Consultant may do so
without liability hereunder provided that notice of such prospective disclosure
is delivered to the Company at least five (5) days prior to actual disclosure,
Following the termination of this Agreement, Consultant shall deliver to the
Company all Confidential Material. Neither party hereto will issue any public
announcement concerning this Agreement without the approval of the other party,
provided however that nothing shall prevent the Company from fulfilling its
obligations to disclose the contents of this Agreement with the U.S. Securities
& Exchange Commission (the "SEC").

         5.       Consultant's Liability. The Consultant agrees to defend, 
indemnify, and hold the Company, its officers, directors, employees, advisors,
attorneys and agents harmless from and shall indemnify the foregoing persons
and entities against any and all costs, expenses and liability (including
reasonable attorney's fees paid in connection with the investigation and/or the
defense of the such entities and persons) which may in any way result from a
breach of any representation, warranty or covenant made by Consultant or from
any services rendered by the Consultant pursuant to or in any connection with
this Agreement.

         6.       Expenses. The Company, upon receipt of appropriate supporting
documentation, shall reimburse the Consultant for any and all reasonable and
actual out-of-pocket expenses incurred in connection with services provided to
the Company, subject in each case to prior written approval of the Company.

<PAGE>   3

7.       Limitation Upon the Use of Advice and Services.

         (a)      No person or entity, other than the Company or any of its
subsidiaries or directors or officers of each of the foregoing, shall be
entitled to make use of or rely upon the advice of the Consultant to be given
hereunder.

         (b)      It is clearly understood that the Consultant, for services
rendered under this Agreement, makes no commitment whatsoever as to recommend
or advise its clients to purchase the securities of the Company. Research
reports or corporate finance reports that may be prepared by the Consultant
will, when and if prepared, be done solely on the merits or judgment of
analysts of the Consultant or any senior finance personnel of the Consultant.

         (c)      Use of the Consultant's name in annual reports or any other 
report of the Company or releases by the Company must have the prior approval
of the Consultant unless the Company is required by law to include Consultant's
name in such annual reports, other report or release of the Company, in which
event Consultant will be furnished with copies of such annual reports or other
reports or releases using Consultant's name in advance of publication by the
Company.

         8.       Severability. Every provision of this Agreement is intended to
be severable. If any term or provision hereof is deemed unlawful or invalid for
any reason whatsoever, such unlawfulness or invalidity shall not affect the
validity of this Agreement.

         9.       Miscellaneous.

         (a)      Any notice or other communication between parties hereto shall
be sufficiently given if sent by certified or registered mail, postage prepaid,
or faxed and confirmed if to the Company, addressed to it at BioShield
Technologies, Inc., Attention: Timothy C. Moses, 4405 International blvd.,
Suite B109, Norcross, Georgia 30093 or if to the Consultant, addressed to it at
Grayson Financial, LLC, 39 Broadway, 21St Floor, New York, New York 10006,
Attention: Gregg deRocco. Such notice or other communication shall be deemed to
be given on the date of receipt.

         (b)      If the Consultant shall cease to do business, the provisions
hereof relating to duties of the Consultant and all compensation to be paid by
the Company as it applies to the Consultant shall thereupon terminate and cease
to be in effect.

         (c)      This Agreement embodies the entire agreement and understanding
between the Company and the Consultant and supersedes any and all negotiations,
prior discussions and preliminary and prior agreements and understandings
related to the central subject matter hereof.

         (d)      This Agreement has been duly authorized, executed and 
delivered by and on behalf of the Company and the Consultant.

         (e)      The validity, interpretation, and construction of this 
Agreement will be governed by the laws of the State of Georgia applicable to
contracts entered into and performed entirely with said state without regard to
the principles of conflict of laws. Any dispute or controversy between the
parties arising in connection with this Agreement or the subject matter
contemplated by this Agreement shall be resolved by arbitration before a
three-member panel of the American

<PAGE>   4

Arbitration Association in accordance with the commercial arbitration rules of
said forum and the Federal Arbitration Act, 9 U.S.C. 1 et seq., with the
resulting award being final and conclusive. Said arbitrators shall be empowered
to award all forms of relief and damages claimed, including, but not limited
to, attorney's fees, expenses of litigation and arbitration, exemplary damages,
and prejudgment interest. The parties further agree that any arbitration action
between them shall be heard in Atlanta, Georgia. Notwithstanding anything
contained herein to the contrary, nothing contained herein shall prevent either
party from, initiating a civil action for temporary or permanent injunctive and
other equitable relief against the other for a breach of this Agreement. The
parties expressly consent to the jurisdiction and venue of the Superior Court
of Fulton County, Georgia and the United States District Court for the Northern
District of Georgia, Atlanta Division for the adjudication of any civil action
asserted pursuant to this Paragraph.

         (f)      There is no relationship or partnership, agency, employment,
franchise or joint venture between the parties. Neither party has the authority
to bind the other or incur any obligation on its behalf.

         (g)      This Agreement and the rights hereunder may not be assigned by
either party (except by operation of law or merger) and shall be binding upon
and inure to the benefit of the parties and their respective successors,
assigns and legal representatives.

         (h)      Consultant is a broker-dealer in good standing and is 
registered with the NASD and the SEC. Consultant is not a party to any
proceeding or action which would prevent it from performing services pursuant
to this Agreement.

         (i)      Sections 4 and 5 shall survive the expiration or termination
of this Agreement.

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date hereof.

                                          BIOSHIELD TECHNOLOGIES, INC.


                                          By:    /s/ Timothy C. Moses 
                                             -------------------------
                                          Name:  Timothy C. Moses
                                          Title: CEO

                                          GRAYSON  FINANCIAL, LLC


                                          By:   /s/ Gregory deRocco   
                                             -------------------------
                                          Name:  Gregory deRocco
                                          Title: CEO