I just leave it in that pot, and slowly bring back up to temp next time with new candles and have had no problems. I do it out in the garage because I am nowhere near careful enough and my wife would end up killing me if I did this in the house and spilled. I am not sure if it is from my dripping on the side of the pot but I do get some smoking going on, or I may get the wax beyond its smoke point if wax has a smoke point like cooking oil does?
<<nitpicking>> Actually, Wax doesn't burn. If it did candles would never work. Wax/parafin has a flash point of about 200ºC or about 375ºF This can be maintained fairly well at the tip of a wick with the introduction of a flame. It's the invisible vapors that can start forming on top of wax that is far too hot that can ignite. Using boiling water as a medium minimizes the possibility of creating a flash point. As with chocolate and custard you don't need all the heat a stove can provide. Plus an open flame such as a gas burner has can be dangerous around vapors. A drop of wax dropped on a red hot electric coil can induce a flame as well, so use the double boiler no matter what stove top you have.. A coffee can or another pan inside a larger pan of warm water is a good enough buffer.
I put the saw dust/chips in the egg cartons and then pour the wax in them. After they cool I break them apart and put them in a plastic tub that I keep near the stove. For my last couple of batches I used noodles and they're a pain to work with.
The reason I mix in chips to wax is the noodles are a pain, and I found doing chips in a carton then pouring wax over seemed to float the chips out and end up with mostly wax and a mess of chips pushed up and out all over.
I can only add my endorsement to these comments. No matter where you melt the wax, use a double boiler for safety and keep a lid near by to put on the pot if you get a flame. Be careful what you put the liquid wax into as well. Much to my surprise, some plastics melt when you pour liquid wax into them.
