I don't know that I'll ever do this, it's more of a thought experiment inspired by Jamie Grant's "Impossible Bottles" (Although if anyone ever wants to buy me a few of these, I'll happily add this routine to my show.)
The magician introduces a corked glass bottle, with a sealed deck of cards inside. He explains that the deck was opened, randomly shuffled and resealed. There is obviously no way for anyone to alter the card order at this point.
The magician Introduces a second, matching deck in new deck order. The spectator is invited to shuffle the deck and place it back in it's original box.
The Effect? Simple: the card order inside the bottle exactly matches the order of the deck shuffled by the spectator.
However, to experience the finale of the trick, the spectator has to choose to ruin the magic of the impossible object.
Is the "satisfaction" of resolving the plot of the trick worth ruining a truly magical object? Does the deck inside truly match the order of the deck outside? Is it worth sacrificing an impossible object to experience a momentary miracle?
Leave the deck and the bottle with the spectator. They'll have the rest of their life to decide.