Just did all my stems using this method and a candle, it's magic. Didn't have to do any sanding at all which is the benefit as sanding takes off layers of vulcinate. It seems like the trick is heating it enough, you should smell a burning rubber like smell, and the stem will become bendy so you have to bend the curve back because it straightens out. Took the sour smell out, this is definately my first choice for quick effective oxidation removal. Did about 9 stems in 30 minutes, went from a dark brown back to jet black, now time to put on some polish to really make them shine