Although head lice are one of the most common conditions for school aged children, they are not known to pose any serious health threat. Usually, by the time an infestation is recognized, the child has had lice for a few weeks (all the while being able to spread them) making "No Nits" and "No Lice" policies a little outdated. The American Academy of Pediatrics (www.aap.org) does not support these policies in favor of treating the outbreak quickly and safely and keeping the child in the learning environment.
It's always best to reach out to your health care provider (physician, nurse, pharmacist) to seek advice on the most appropriate treatment. Many home remedies are available but lack the scientific evidence to prove their effectiveness and safety.
This website has a comparison of available FDA approved treatments: http://www.myheadlicetreatment.com/head-lice-treatment-options/product-comparison/
My kids haven't gotten head lice yet. I may have had it when I was 10 and was treated with a lindane based shampoo. I wouldn't let my kids near the stuff today. Amazing how quickly things change from one generation to the next.