Over the past several years there has been some speculation about the toxicity of "over the counter" and prescription head lice treatments. Some doctors believe that too much toxin makes it into the blood stream when using these types of treatments; this is especially true for children, and pregnant women. The level of toxins that could make it into the blood increases with repeated use, which may be necessary in the case of a re-infestation.
Another drawback to these "over the counter" and prescription head lice treatments is that the lice are becoming resistant to the pesticides in the treatments. This often results in either the treatment not working at all, or a very quick re-infestation.
As a result of the toxins in the treatments, and their increasing inability to kill lice, many people have turned to home remedies. While healthcare professionals have recommended some of these home remedies, others have been used for years as a treatment for head lice.

Mayonnaise: Pediatricians often recommend this treatment as an alternative to commercial treatments. Saturate the hair with real mayonnaise, and cover the head with a shower cap. Let the mayonnaise sit in hair for at least eight hours and then wash out. After washing the hair, carefully run a nit comb through the hair to remove lice and nits. The treatment should be repeated every few days for about a week and a half.
Listerine: Saturate hair with Listerine and place shower cap on head; leaving it place for at least 2 hours. After this, rinse hair and comb with metal nit removal comb. All lice should be dead at this point. Next you will need to saturate the hair with white vinegar, and again place the washed shower cap on the hair for 1 hour. After 1 hour, you can remove the shower cap to shampoo and condition hair. Again, comb hair with the nit removal comb.

Coconut Shampoo & Tea Tree Oil: Use equal amounts of tea tree oil and shampoo. Lather through hair and then use a shower cap. Let the mixture set on the head for at least two hours before rinsing. Apply a coconut conditioner, and carefully comb hair with a metal nit removal comb. Use this treatment at least three times over a two-week period, making sure to comb through the hair each time. Wash all bedding, as well as coats and scarves, and soak combs, brushes, and other hair items in boiling water.