I have two girls that had bouts with lice last year (PreK 3 and Kinder), and they returned to the same school this year. I tried a couple of the over the counter stuff (Nix, etc) to no avail. Mayonnaise didn’t work either…I had to do that one on myself because they got into my long hair as well eventually.
The only thing that truly worked was investing in those special combs (I picked them at WalMart) and consistently combed the hair out during the “conditioner” part of their shower.
We did this every day for 2 weeks at first, and eventually 1-2 times a week. This was the easiest way to make sure we kept the lice at bay.
This whole discussion reminded me to get the combs ready for this new school year. good luck!!!