White vinegar is not used in the treatment of adult lice. However, a mixture of vinegar and water aids in the removal of nits from the person's hair after the treatment to kill adult lice, according to the Minnesota Department of Health.
Nits do not fall off the hair after treatment for lice but cling to the hair follicles close to the scalp. Removal of nits is difficult. Combine vinegar and water in equal parts, and spray the mixture directly on the hair, explains the Minnesota Department of Health. Let the mixture soak on the hair for 30 to 60 minutes. After removal of nits, thoroughly rinse the hair.