I love this effect, performed it many times. I'm curious about one thing...when you're performing this for a spectator and you take the cards out of the box, where do you put the box? If you don't do this already I suggest placing the '
special' side of the box down onto the palm of the spectators outreached hand.
It still gives them one free hand to select and hold the card, plus at the end of the effect they have been in control of the box (in their mind) the entire time.
Better yet, learn how to do the '
DG Box Steal' then have them "freely" select the a card...look at it, place it into the box, you close it up...have them reach out their hand, give them the box to hold with both hands (
special side down).
Wave your hand over their's slowly, then tell them to open the box...their selected card is gone and they will be like "
WTF?!", but then you say:
"
Look...see how it says Bicycle?" and as you say
"Look...", you'll already have your hand over the 'special side' not even giving them time to see it because in their mind they know it says "Bicycle", you rub the box with your fingers slowly revealing their card on the box and then hold on to your pants, it will blow their minds.
I'm talking fragments of skulls and blood spatter on the wall behind them.
- Steve
Postscript: Also, if you had Ultra Smoke 2000...imagine the reaction of rubbing the box with your fingers and then smoke coming from your hand as you revealed the box with their card written on it.

BAM...
S.