I'm a fan of wax worms. I like crickets better, but wax worms always seem to be available these days and crickets aren't. I don't really have any advice on keeping them long term though. There's enough time between my fishing trips that I don't try to store them, I always give away any that are left when I'm ready to leave the lake. I usually buy them the day before a planned trip and put them in a small cooler with a blue ice pack in it, but not touching the bait containers. I replace the ice pack the next morning and keep them that way while I'm fishing. It seems to keep them nice and lively. Do the same with red worms since my son has more confidence in them than wax worms.