To treat head lice with Listerine, soak the person's head with the mouthwash, and soak it again with white vinegar. Shampoo the hair, and then comb out any visible lice eggs, or nits.
- Soak hair in Listerine
Pour enough Listerine on the person's head to completely soak their hair. Gather the hair in a plastic bag or shower cap and let it sit for an hour.
- Rinse and soak with vinegar
Carefully rinse the Listerine from the person's hair. Soak their hair in white vinegar and wrap in plastic bags or a shower cap. Let it sit for an hour.
- Rinse, shampoo and comb out the nits
Carefully rinse the vinegar out of their hair and shampoo as normal. Comb out the hair using a nit comb.