How long do you leave Listerine on hair to kill lice?
How long do you leave Listerine on hair to kill lice? We suspect that the alcohol in old-fashioned amber Listerine kills lice. We would discourage spraying it on, though, as the fumes might be inhaled. Gently massaging the mouthwash into the hair and covering for a few minutes with a towel should do the trick. What instantly kills lice? Wash any lice-infested item in hot water that is at least 130°F (54°C), put it in a hot dryer for 15 minutes or more, or placing the item in an air-tight plastic bag and leaving it for two weeks to kill...