I feel for you. My kids just got sent home on Friday because they picked up lice from who-knows-where. I have 3 girls with longish hair, and it's such a pain to get out of my oldest daughter's hair.
So, I hate pesticides, and I have lice. I buy the Suave Naturals Coconut shampoo and conditioner, put some tea tree oil in each bottle and mix it. Then I wash their hair out, and then let the conditioner sit for at least 20 minutes to really get it into their hair. I bought the Rid metal comb set - they're about $8 at WalMart in the pharmacy section - it comes with a short comb for the bugs, and a long comb for the eggs. I only use the long comb though; it seems to work for both purposes. Anyway, get a claw clip or two to section off your daughter's hair and comb thru one section at a time. When I do this, any bugs I've pulled out are dead and the eggs come off the hair much easier.
I recently tried a recipe that calls for mayo, white vinegar, and tea tree oil and that worked awesome. My kids are ready to go back to school already