Nice. I be looking forward to it.
I have played through most of the game and what I´ve seen so far is: The bite-gag which is the only type I´ve seen that can be worn on the player-character. I guess you could count the hoodie as well, but that goes over the whole face.
The other is the cleave-gag when interrogating Marin, loved that scene btw, and when getting revenge on her. But, that gag is only seen on her.