I like the idea that the rate of switching between states is important, though I'm not sure about why high cadence should be particularly useful.

Five years ago I built a simple machine to give forced exercise to the arms. I posted on this at:
Forced exercise of the arms

The results for me were mixed: bradykinesia down, tremor up. Note it wasn't a double blind test, so there's a lot of opportunity for the placebo effect to play a part.

John