Head and public lice can be killed quickly, easily, cheaply, and safely with mayonnaise. Buy a new jar of real mayonnaise as one in the refrigerator may be too cold and old. Grab several handfuls— to cover all the hair, being sure to get behind the ears and down the neck a bit.
Cover with a disposable plastic shower cap to keep the mess to a minimum. Leave the mayonnaise on for two hours to smother the lice and developed eggs. Remove and dispose the shower cap, wash the hands well, and shampoo. It may take two or more shampoos to get the hair clean.
The mayonnaise may not kill the newest nits since the unborn lice inside may not have developed enough to need air yet. To deal with nits left behind, under good lighting (such as natural sunlight), comb out any remaining eggs with a fine-toothed metal comb. Nits are usually found near the scalp.
Check the hair by tiny sections, especially around the edges of the hair, at the neck, and behind the ears. Put each nit or hair into a bowl of vinegar. Flush away any contaminated tissues. Boil the comb for three minutes in water or throw it away after use.
Repeat the smother-the-hair-with-mayonnaise-technique seven to ten days after the first application to kill any survivors. Continue to check the hair daily for a few weeks since you or your child may still be around others who are infected.
This How to kill lice quickly adapted from:
The Country Almanac of Home Remedies - Brigitte Mars