I use six screens only....the trick is to draw slow and steady.  My only misfire was because I worked myself up to the point that I sucked too hard from hyperventilating.

I can't find choreboy and don't want to order online...did find some albertsons brand but when I would burn off all the crap it wouldn't stop flaking off even after a solvent soak or two. Major turnoff...wonder if choreboy is a thicker more pure copper than albertsons brand?