Have you tried tea tree oil (melaluca)? I used to get lice BAD in the summer when I was a kid in Florida, and my mother would have fits trying to get rid of the lice. The nit comb, sometimes mayonnaise would work (suffocates the lice), or tea tree oil. The tea tree oil worked the best. Also, you can use vegetable oil in a comb to get them out of the hair if they're sticking to it like glue. I hated it, but it worked for me! Hope this helps!