Oh, man. With 4 kids we went around and around with this for about a year. It's incredibly aggravating and time-consuming.
Get a long-toothed metal comb (We found one called "Lice Meister") You need great lighting - I took my kids outside, and the sunlight helped with spotting the little devils. We had the best results with the homeopathic remedies, and one called "Hair clean- 1,2,3" containing coconut oil, anise oil, Ylang Ylang oil, and isopropyl alcohol.
We also have not had a problem since we joined a fitness club where the kids swim in an indoor chlorinated pool.
Good luck. Sharon