Hi Jules, any kind of vinegar- cover the hair completely in vinegar for about 30-40 mins (dependant on the legnth less if short, more if longer.) then really wash it out with shampoo. once you have shampooed the hair put on condtioner and leave it in whilst combing the hair with the flea comb, make sure you have tissue to wipe the comb and get off ANY loose fleas or eggs and repeat as long as possible, my little sister used to suffer really bad with head lice and she has very long hair. Hope this works :)