I personally do not like RID, I have used NIX in the past and found that going nuts cleaning every inch of your home is not only expensive, but exhausting.
Ours came from some one who visited our home (apparently infected and we weren't aware of it), not from the kids bringing it home from school (as I had school-age kids). Once you have the head lice treated, place him/her in a clean room and then when cleaning the rest of the home think about where the hair falls and vacuum that area up then clean out the vacuum immediately! I found the sprays to be a waste of money and would not personally recommend them.
Rooms with carpet or a lot of cloth furnature are the toughest rooms to clear up during the cleaning process.
Also wash all clothes that have come in contract with the infected family member.
Don't forget to follow the instructions on the treatment shampoo and continually monitor not only the infected but also the uninfected to make sure the lice don't continue to spread. Also, remember to retreat with a second treatment as the instructions state in approx. 10 days (if I remember correctly on the number of days).
If you have any problems getting rid of the lices, contact your doctor or health department for further information on how to treat head lice.
The key is to catch it early and monitor it until it is gone completely.
Move of a preventative measure in between head lice shampoo treatments:
I've also used Mayo in combination with the NIX for better results. It smells and is messy, but it works! Coat hair with Mayo, put a Walmart bag over the hair, tie the handles to stay in place, and use dawn dish soap to wash out the mayo the next morning. I did this over several days and while the kids did not like it, they liked it better than the head lice.(I had teenager girls at the time.) This was done after treating the hair with NIX and removing the head lice and nits from the hair.