Handbuch der Magie (German book) by Jochen Zmeck Page 128 et seq.
Personal Comment: This is cute and kills. Hard to believe I know, but I tried it. People seem to dig this cute story. Personally I would change the method drastically, but the book that this is in was written for laypeople ergo this is simplified. The routine has a fulfilling climax and could be a neat encore trick.