There has been much talk about newer therapies for treating resistant lice such as applying full fat mayonnaise, olive oil, Dippity-Do brand styling gel, or Hair Clear 1-2-3 to the hair overnight. This is supposed to suffocate or smother the lice, and while this is probably safe to do, it is messy and probably unnecessary – especially if you are persistent in manually removing lice and nits. To remove vaseline from hair, consider using baby powder and a liquid grease-cutting detergent.
Some physicians are using oral therapies to deal with resistant lice, including the drug ivermetim (a one time dose) and the antibiotic Bactrim (3 day course).