Headlice are a NIGHTMARE to get rid off. But I have to say, DO NOT waste your money on the insecticide treatments that claim to kill the lice. They don't work. The headlice are immune to them. After much combing I finally decided to resort to the chemicals, expecting our problems to be over, but the lice were still alive the next day. It didn't help at all.
We had headlice for months, and when you co-sleep it is impossible not to re-infect everyone. But after a bit of reading I finally got rid of them! We've been lice free for months now!
I got myself these combs: http://www.chc.org/products_kit.cfm
The company is based in the UK, but I'm sure you could find a similar product locally. They're just combs with very finely spaced teeth. What you need to do is wet the hair, then put on conditioner. Loads of it. A really thick white coloured conditioner is best. Detangle the hair with a widely spaced comb, then comb through in sections with the lice comb. After every sweep with the comb wipe the conditioner off with a piece of kitchen paper. The lice can't easily move about in the conditioner, and apparently it blocks up their breathing aparatus and they die. Next rinse the conditioner out the hair and move on to the next person. You really have to treat everyone on the same day. I just lined the kids up on chairs and put a video on for them to watch.
I can't find the exact info right now, but it was to do with the life cycle of the lice. It was available online. You need to comb on certain days to get rid of all the lice. I remember you had to comb everyday for 3 days. The first day i got almost hundreds of lice out of their hair. The next day there was less, and the day after there was only a few smaller ones. After the 3 days you had a day or two break and then you started combing again to catch the lice that had just hatched. Eventually I got rid of them all.
The kit I bought had a purple comb that removed the eggs and the egg casings. It really worked. Some of the chemical treatments claim to get rid of the eggs, but they didn't. The comb was great! The eggs are really glued on, but the combination of the comb and the conditioner removed them.
Edited to add the web address for the treatment program. Its a bit technical really, but just scroll about half way down and you find the days to comb on. http://www.microscopy-uk.org.uk/thel...heprogram.html