When getting my glider rating, I learned to stall by keeping the wings level with the rudder, no using the ailerons. There is no ball, and the string is ignored.
I've noticed myself naturally doing this in powered craft since then, and it seems like a good idea. For a banked stall, obviously using the ball for coordination makes sense, but if you're going straight and keep the wings level with the rudder, you can't really be out of coordination. To me, this is a much easier and safer way to teach stalls. It's a bad idea to use aileron to level the wings near a stall, using rudder and NO aileron seems like a better way to teach stalls. And it's easier for a student than worrying about looking at a ball.
I've noticed myself naturally doing this in powered craft since then, and it seems like a good idea. For a banked stall, obviously using the ball for coordination makes sense, but if you're going straight and keep the wings level with the rudder, you can't really be out of coordination. To me, this is a much easier and safer way to teach stalls. It's a bad idea to use aileron to level the wings near a stall, using rudder and NO aileron seems like a better way to teach stalls. And it's easier for a student than worrying about looking at a ball.