It does require particular flame settings, and bead heat and reduction duration are more critical. My specific timings work for my specific set up.  It is going to vary from person to person.
Here is my process.
1) Shape bead
2) Allow bead to cool for 20 seconds.
3) Adjust flame so candles are stretched 2mm from neutral.
4) Pass bead through flame, candles should touch bead and deflect yellow flame around the edges. 1.5 seconds duration for each pass.
5) Allow bead to cool 5 seconds between passes.
6) Repeat pass-through and cooling cycle 5-15 times.
7) Anneal.