I'm not a big fan of inhibiting my lee's laughter, either. A few times it's been a necessity, tho (think motel rooms). I have a couple big 2 1/2 or 3 foot square silk bandannas (would work with any comfortable matierial-probably better since silk knots are kinda slippy), and I tie a big huge, bulky knot in the center. Actually 2 or 3 on top of each other., then I just tie it off like a cleave gag. I like the look of a cleave gag (useless for killing sound), and dislike ball gags. In most mouths I've run across, the knot is big enough that it stuffs the mouth sufficiently to mute the sound. Looks good, one piece, and it absorbs drool a lot longer.
But I only ever use them when sound is a real issue. Think the last time I used one we still lived in Ohio, and we were visiting my parents.
Christopher