Can be done, after all other types eg ATR's and Saabs, have prop brakes as options which not only will hold a prop but stop it with the engine running.
The obvious danger aside, whether or not its possible with your own hand is debatable. Saabs will break a prop strap on start if still attached and I doubt anyone would be strong enough. If it started to move, there'd be no stopping it.
May be better asked in the Tech Log forum?