I make candles but I never actually considered the possibility of using a crockpot to melt the wax! That's ingenius.
I see that you actually posted this quite some time ago, but I had to respond since this question is right up my alley. Since November, have you tried this? I would love to hear your results. I'm tempted to head to a thrift store right now and pick up a new aging crockpot to test this with!
Although one worry I would have is how to clean it - as it is, I melt wax in very small batches and have three Pyrex containers on my stove top, one for blue/green/purple candles, one for yellow/orange/red candles and one for white. I started doing this when I realized I could never get QUITE all the wax out. I wonder if three different crockpots would be overkill.