I've had success with playing with boot polish to reduce the drag whilst stropping, Good quality blacking in a tin (ie, Kiwi brand shoe-polish) rather then the crappy liquid inna tube. Polish to reduce drag/stickyness and Leather Conditioner (I generally use Saddle oil for this) to build it back up, With these two things, I've managed to adjust the draw somewhat to my liking on my strops.
Mind you, I don't know how the blacking affects my stropping, it certainly doesn't seem to affect it Too badly.