Gags
Gags from the first one to the last: soft silicone with breathing holes for a beginner, a bead gag that is easier to hold for an hour, a bell gag that reports every movement, a lips gag that holds the mouth open, and the head rigs: the Wearable Gag on a full head harness, the Nose Hook Gag with its spider ring, and the Funnel Harness.
A strap gag is a mouth thing; a harness gag is a head thing, and the person wearing it stops being able to look away. Start soft.