Just email him for instructions. I would suggest using the supplement suggestions on this site rather than those from Dr. Wilson. Analytical Research Labs and Trace Elements, Inc do not wash the hair. In the JAMA study referred to by Dr. Mercola, the labs that wash the hair produced erratic results. This is also what was found in earlier studies.
Hair is biopsy material and harsh washing chemicals damage it.
Great Smokies Diagnostic Laboratory. Their analysis is more extensive than many labs. I have talked to one of their research scientists about analyzing for additional minerals that I feel are important in thyroid disease and they seem open to that possibility. King James Medical Laboratory. The hair analysis company is Doctors Data.