The Middle Distance

I would have to say that the answer depends on one thing and one thing only - which answer do you think would make your story better?

However, if we're having the conversation purely for the sake of semantics and detail, I'd have to say that my personal guess would be that the cock would NOT disappear, because while clothing and so on disappear, the cock is part of another person and I'm fairly sure the good professor would regard the body housing a soul to be different from soulless clothing.

...And man, thank you for including the "Assuming this person is neither Sauron nor Tom Bombadil" caveat up there, because in the grand tradition of "Don't think of pink elephants," you can now guess precisely what it is I am now completely incapable of not picturing. With Galadriel in there, too, of course, just for the hell of it. And Gandalf watching while smoking his pipe. *facepalm*