Unfortunately, it is All or None. As a pro user, you could keep the MM out of your Compendium Sharing and transmogrify them in from a different game, but that seems really clunky, and unrealistic in a world where you players could easily buy their own copy on the MM in print or digital, or consult the SRD, or just google search for statblocks. There's no way to keep this info out of the hands of players, regardless of how or where you play. It's a group discipline matter. Some GMs switch up the printed stats if they cannot keep their players from checking.