I know that in the volumes you’re dealing with, it’s probably not a problem… but acetone fumes are NOT to be messed with. I wouldn’t put that anywhere near a heat source (same goes for Mineral Spirits and lighter fluid, mind you!)
As suggested, use canned air or air from an air compressor if you happen to have one. If you’re using the canned stuff, don’t do a bunch of bearings at once (or overdo it on a single bearing) because it WILL start shooting out condensation eventually.
I have pure acetone and also mineral spirits, and I find that I’m skipping the acetone phase that I used to put the bearings through–sticking just to mineral spirits–and I’m getting the same or even better results. I’ve been told to use acetone for the ceramic/steel bearings, though, so I’m sticking to that.