I use a crockpot because it
1 - Holds the vermiculite
2 - Has a lid to cover the vermiculite when not being used.
3 - Looks prettier in my studio than a coffee can would.
As for turning the crock pot on, I don't even have mine plugged in. The only time I've had a bead break when cooling it this way is when I can't stand it and take it out of the vermiculite for one last peek. When I have enough beads, I kiln anneal them. I've had a couple of people want to see how strong these are so they've dropped them from a second story window onto their driveway, and they bounced instead of breaking.