Have him send a couple of full body nude pics, and a scan of his ID, by e-mail.

If he's legit, he'll acknowledge that that's part of the "audition" process.

That way you have some info to share with a friend of yours before you go there - in case you don't come back whole. If the pics and ID don't match, or who opens the door doesn't match, you'll have the basis for a decision before you go or go inside.