Why would you want to make a bet then trick the casino into believing you didn't make a bet?
If you are making coin-in but covering up coin-out by pulling the card then you must be in a spot where freeplay is issued according to losses rather than wager and theoretical house advantage.
And I still have a problem with you saying you have employee's. I don't think you do in the classical sense. And I don't understand why someone would work for somebody else when they could do the same thing themselves.