Recent studies show that while white vinegar does loosen nits from the hair shaft, it also can deactivate pesticides such as Nix. As a result, I no longer recommend using white vinegar in conjunction with these products. Another no-no with lice medicines is the use of hair dryers, including blow dryers. Many pesticides work by leaving a residue on the hair that continues to kill lice and nits for several days. The heat from hair dryers may deactivate the chemicals and undo all your efforts.
Most alternative treatments are untested, but early reports are promising.
Cover the infested head liberally in Vaseline. Then shampoo the Vaseline out of the hair. The upside is that it is not toxic, and from all reports, it seems to work. Washing the hair with dishwashing liquid, which has a degreasing agent in it, may help. The Packard Children's Health Services Pediatric Hotline at Stanford is hailing another popular treatment.