"Practicing" on the bench

[Amesman]

Have not found anything (or at least have not been looking in the right place) for this one: Is there a rule prohibiting a player(s) on the bench from warming up with a ball during the game?

Could mean just flipping the ball hand-to-hand or flicking short shots up in the air while on the bench.

Or, during a timeout before attempting free throws, a player grabs a ball and starts practice shooting the ball straight up near the huddle. Or could be a cold bench player being called in to shoot technical FTs, wanting to get a better feel.