I made these for Rowan, and they have done wonders for our bath time routine. Normally, he fights me tooth and nail to go up for his bath every. single. evening., but, when I showed him my magic surprise filled bath bombs everything changed. And even better, the soothing lavender essential oil relaxes him while he bathes, win, win.
I also think these would make a interesting party favor. The kids could bring them home, and pop them in the bath to reveal a special surprise. Rowan had a blast dumping them into a big glass jar and watching them erupt. Try it.