Commercial blends like MSW and Silca have a bunch of low friction additives that you would lose as these also settle at the bottom.
So when using these it is best to ensure the chain that goes in is as free as possible of superficial grit (microfibre cloth or cloth plus a few sprays of iso to wipe the chain externally before immersing it). Even so not much comes off riding in mostly dry conditions. To extend the life of the wax one could still shave off the bottom at some stage but I prefer to have all the friction goodies and will rather start over with fresh wax at that point. Pulling out the metal shavings is probably as far as I will go.
If I was just using some straight wax base then I would put a shallow steam tray in the pot to keep the chain off the bottom and with no need to stir up the wax you'd be immersing in the clean upper layer.
How do candles work for you? Have you ever compared it to other bases or specific chain wax? I keep hearing that candles are the worst option, but I am sure there's significant differences in mineral oil content there and some could work better than others.
If all the ladies in the neighborhood were to stop donating scented candles to me I might try a commercial chain wax. But with the scent that comes off the wax when I'm over in the normally "locker room smell" rec room where I do my chain servicing, everyone seems to appreciate the fragrance. Unfortunately, I'm exposed to lots of rainy mist here and I ride daily, so I'm swapping chains every couple of weeks no matter what I use. At least waxing is a relatively clean process compared to most oil types that I've tried in the past.