I'd have to think about it more, but on the face of it I think that it sounds okay. Refs already have the power to blow the play dead for a number of other reasons, why not stop it if a player is stalling the game? If you threw your body down on top of the puck so that nobody could move it they would stop the play. Likewise, closing your hand over the puck is already a penalty. I see some rationale, and precedent, to what you're saying.