I use one quite a bit. Probably cleaned close to 100 pipes using the same one. I use a propane torch for the heat source and have never had a problem. I came up with a rubber cork system with a vent hose I use in place of the cotton. Keeps me from getting alcohol on the finish most the time. If you do get it on the finish, quickly wipe it off and there isn't a problem as you'll want to buff afterwards anyway. Take special care with lucite stems as too much heat will melt them inside.