@irontoenail - You don't have to just use round beads. You can experiment with almost any kind of glass bead, as long as it is all one color. Multi-colored beads tend to crack in half.
You might even be able to get glass beads with holes in them to work, although some of them might also crack in half in the water.
Just be careful and keep a lid on the frying pan. Although I've never heard of one of them popping, I always do just in case.
It's less expensive than buying vintage crackle glass which is quite popular.