Just noticed this question. I'm a school nurse--I know way more about lice than any human being should!
Olive oil works fairly well. Leave it on for a couple of hours, wash out with several shampoos. You might want to repeat it weekly while the outbreak is going on.
For nits--here's a great school nurse trick. Slightly diluted fabric softener on hair, cover with a plastic shower cap for half an hour, rinse out. It unglues the nits.
Whatever you do, don't use petroleum products--vaseline, baby oil, mineral oil. And obviously, no gasoline or kerosene either (I only mention this because people actually use these!) It takes forever to get non-vegetable-based oils out of hair. And they're no more effective. Be sure to vacuum carpets and mattresses well, along with what you're already doing.
M60 H52 D20 M14 yrs OW-old gf from 1986 bomb-5/18/08 H filed for D-9/10/08 D final 4/24/09 xH remarried (not OW) 2012