Yeah, me neither. I don't see how to do that without strong yaw control, or flat spins for that matter either. Knife edge is of course out of the question. But many key staples of an aerobatic routine can be done with just bank, yank, and a lotta power. Loops, immelmans, rifle rolls, etc. Hammerheads are kinda possible if you enter the climb a little off vertical, but are not very reliable in my experience. Or maybe I'm just not good enough for that.