I'm in the process of switching over to this method myself. It seems like a worthwhile winter task. I'm using my heated "Prosonix" 3.5 gallon ultrasonic cleaner to clean and then to work the heated wax into the chain. I may have to switch to a small crock pot but so far, when I place a pyrex 4 cup measuring cup with the wax granules into the hot water bath of the ultrasonic - it seems to be working. I can see why getting the chain, the chainrings and the cassette as clean as you possibly can will improve your results of getting (clean) wax into all the places you want it.