G.♣.
I guess my philosophy is, lice happens. I believe I got lice twice growing up and once as an adult (when my son came home from preschool with lice ... fun!). It sucks! But then you wash the hair and comb the hair and vacuum and wash the sheets and bag the stuffed animals and eventually you get to have a life again.
It's definitely a pain in the butt, but it's not the end of the world. As far as I know lice aren't harmful. But they sure as heck itch!
Really, the best thing you can do to avoid getting lice is to not share hats or hair brushes. I don't really know anything about repellant. It could be somewhat new, or it could be that I just never heard of it.
Try not to worry too much. If someone in the family gets lice, you'll deal with it.
Ok, now my head itches ... but I'm pretty sure it's just psychological.