My husband worked in a residential facility for foster kids and dealt with this a lot. It sounds like you're doing all the right things. He did mention that the mayo trick worked for them. I'm sorry you're going through this! We don't have kids, but I remember having lice once or twice as a kid and now that I think back on it I feel sorry for my mom - she must have had the creepy-crawlies the whole time she was treating my brother and I!