When chasing from foil relying on the sound of it is probably not the way to go! Watch what’s happening and feather lightly, whilst slowly decreasing the distance between the foil and flame and you will hit a sweet spot. The flame should be slightly beyond the substance to be vaporised and the foil tilted at something like a 45º angle. I think there is quite an art to chasing, and can see it being quite wasteful until you get the technique down.
Whilst this this technique works very well with gear I’m not sure it’s ideal with spice. I would recommend a pipe or bong with ash or a leaf bed.