I have a guess, it's bold it would definitely work, and it's not something I would be comfortable with doing outside of a stage show perhaps. I don't know what he did before the camera but I'm not sure if it matters. No, I don't think this is published anywhere. I disagree with ID4, David has lots of people working for him and creating magic. He has performed a bunch of magic created by the likes of Danny Garcia, Dan White, Calen Morelli, Blake Vogt and on and on. A performer can require them to sign exclusive contracts so they can't publish the tricks elsewhere.