Yes it does kill already hatched lice. However it will not kill the eggs. If youre looking for a natural remedy try this site, its very thorough. Good luck! Http://lacetoleather.com/ridlice.html
My daughter had lice and we tried the vinegar method and it worked FINE!
Yes, that's a solution. Usually lice are attracted to clean hair instead of oily dirty hair. So when you surprise them with vinegar, they wouldn't know what hit them.