@Toraish:
I know, yeah, concrete proof is impossible to find. Which is why this whole argument is silly in the first place, but it is what it is. Anyway, I don't think it's much else than just overloading your consciousness with strong pain impulses for a minuscule amount of time. Strong pain always numbs even the hardiest of organisms, it's just a question of how quickly they recover back to full functionality. And in the case of the strongest and most resilient fighters, which Momonga can definitely be counted amongst as a vice-admiral, that time is very short. Especially when you consider what kind of damage he sustained.
Basically, a dagger through your palm hurts like hell for a split second and stops you from turning into stone. But since it isn't a very serious injury for someone who can recover easily, Momonga had no problems doing that.
Well, your argument would be really good for real world. It's nit like the explanation is bad, but than pain was also what allowed Momonga to take eyes off Hancock, so with some additional facts it's not possible to continue this discussion.