In my humble opinion the trick can be done anywhere in the world. Why? Because the strongest part of the effect is the fact that they the spectator can see and touch everything, in the end they get to play with everything and you are clean. Transposition effects are very strong for any person, the fact that they are holding the Silver Coin and they see the change that is what fries them. Also they see both side of both coins.
When I started playing with the effect I also had multiple sets (effects) but with time I realized that is better to set my audience for the kill and just hit them with what is now Digital Dissolve. Dan White Killed the people on the DVD, well you can see the guy running away in the preview. It’s not that I don’t like multiple steps but when you can hurt and audience right from the start and come strong, that to me is Magic! Also coin tricks can get complicated follow this, then look here, check this out, etc... here they know whats coming but can't explain how.
bjBueno