I remember the exact form of how to do it, all I need now is practice. Also, who knows? Maybe completely no bounce is possible. After hitting a shot with only 1 ball's height I reckon it could go even lower. Also, I was very surprised that I needed to add SOOO much more spin onto the ball, even with the opponent's topspin. And the ball is just above waist level, not a smash like the OP adding to the difficulty. Even pros find it difficult to put heaps of slice on the ball when it is low. So when I can hit it about 6/10 times, I'll work on Houou Gaeshi.