I was taught ball fall arm to the wall myself, I never got the chance to try this swing myself, I did it for the first time yesterday from a no step at the foul line drill type movement and I really can see how you can develop some serious power and revs with this type of swing. I just wish I could bowl so I could implement it into my game.
The drill I did was I went to the foul line and just let my arm dangle with my wrist in position and used my balance arm to propel the ball back and forth a few times until I got the feel of it then release the ball at the right time.
If I could bowl I would work my way up from that to a bigger and bigger swing then a one step delivery then a two and so forth until it was part of my normal approach. It might take a while is my point lol.