I know what you are talking about, and I have done this before. I am not sure if its proper technique or not, but an easy way to do this is by holding the racquet with a backhand grip and just swing full power like you normally would with a straight smash. The shuttle will leave your racquet at the speed of a normal smash, then it will slow down tremendously when it reaches the net. It looks and sounds like normal smash, so if you can pull it off, it can be very deceptive. By the way, if you are right handed, the shuttle should go crosscourt from right to left. Hope this helps, try it out and tell us if it worked out.