Personally, I haven't the slightest, but after something in the vicinity of two and a half years, I have finally succeeded. On Sunday, I landed hard, and wrong, on my left hand, and sprained both my thumb knuckles.
Not that I let that stop me from playing today; before playing, I finally went out, got a splint (finding one long enough to protect my entire thumb was interesting), and first-aid tape to apply the splint. When I'm wearing my biking gloves (which I do when playing Ultimate), the splint does its job quite well (tape to immobilize the top knuckle, and the glove holds the splint in place to immobilize the other two joints), but I'm still trying to figure out if it's possible to immobilize both knuckles with just tape; the proximal phalanx is entirely too well surrounded by flesh (mostly muscle) to get a good tape job. Fortunately, I don't need to immobilize the joint at the base of the thumb (right next to the wrist) too, or there'd be no solution other than the gloves; tape around the palm is a non-option, due to the shape of the splint. And the fact that it's notoriously impossible to apply tape to a palm.