I don't see how that proves your point though, as other people said, it's about the finger going through the hand. You may be able to make it with a tube, but who's gonna use a tube to see if their finger goes into their hand? All you do is try to poke your finger through your hand, which is very simple. You may be able to create a illusion with the tube, but your not actually putting your finger in your hand.

Sorry if I missed a point of this thread.