Arousal Switch
Sometimes focus is difficult, because you are in a body, a role, a reality which encourages you to be aroused quite a bit of the time. Your body might be unusually sensitive, or the fantasies born of hypnotic pleasure might be just a bit too distracting.
So what if you changed the rules?
A trigger focused around a specific type of stimulation. All sexual excitement, all sexual arousal, must begin with that trigger. Any other time, your body simply has its erogenous zones and genital response switched off. There is no stimulation in all the world which will matter. Arousal, fantasies, your distractions of desire, switched off.
Until a finger, a toy, a device, is pressed against your rear. When something slides inside your butt, your arousal is switched back on and your sexual response will be as it once was, until the stimulation of your rear ceases.
Also includes language allowing for the underlying trigger state to be removed: having vs. not having this arousal switch involving your butt.
Especially good for analytical and literal minded subjects.