You have to be careful with this sneaky tactic. Once you lift your back foot you have disengaged the rubber. Most rules state that it is a balk to go through part of your normal delivery while NOT engaging the rubber.
I've seen this move attempted against my team once. The pitcher had obviously practiced it because he was smooth and it was very subtle. In fact, the umpires didn't even notice it. I recognized it right away and told our runner on 3B to get back so it didn't work. Then I had a friendly chat with the umpires.