Or, get two of those clear plastic film cannisters (any photo processing place has buckets of used ones). Cut a circular hole through each of the tops, so all that's left is a rim. Cut two identical pieces of dental dam big enough to cover the cannister.
Take one piece of dam, load the dime, then put it over the cannister and seal it with the lid/rim. Put this in your left pocket.
Put the duplicate cannister, lid, dam, and dime, in your right pocket.
Bring out the cannister, lid, and dam. Show them around, and snap the lid over the dam, matching the preset cannister in the pocket.. Now remove the dime, but do Tamariz's Double Crossing the Gaze switch, changing in the prepped cannister as you (apparently) search for the dime in your pockets.
Show the dime, put it on the dam, etc.
I know, it's a bit of effort and not quickly resettable, but seriously -- who would that not kill?