Useful information and cautions at: LICE
Over 12 million cases a year in the U. S. The possibility of lice mutating to resistant strains because of improper use of treatments may be a real problem. Lindane is harmful to the environment. As I said, use with the consultation of a skin specialist.
The alcohol-vodka treatment is OK for most people, but some develop a bad skin rash. Note- most plastic bags "breathe" so you end up with water vapor in the bag. Drugstore alcohol is cheap, so use fresh each time.