Whack!

I did this exercise the last couple days: holding the racquet with a Continental grip, I bounce the ball off the ground and whack it against the wall as hard as I can with as little effort as possible. It comes out as a slice or a chop. I think of trying to slice the ball in two with the leading edge of the racquet frame; inevitably at the last moment the wrist pronates by itself, and the racquet face hits the ball, sometimes for a very flat shot. It comes out harder if I flick the racquet. It's a nice feeling of generating immense power with very little effort. I then try to replicate the feel when serving. If I tomahawk at the ball at about 45 degrees to the baseline, I can generate very flat and hard serves down the T. The point of this is that it's impossible to whack the ball hard by muscling through it, so I'm trying to remember the muscle feeling of the shots that come out hard with little effort.