a snorkl mask or some goggles ?
Joking aside, why don't you just disconnect the wand ? so no vapor will escape the whip ?
Coz as far as I know if you plug the hole the vapor just finds another path to escape and the herb is percolating therefore loosing its goodness.
Basically, the only hands free design for a gamer that wants to be able to vape without worrying ( note that this is impossible when smoking) is a bag style vape.
You can attached the bag to a folded arm (like those desk lamps have) so the mouthpiece will be next to your head. Turne your head toward the moutpiece, press the valve with your mouth, inhale.
Hope that make sense but not sure it will help