Years ago I had a gal-pal that came up with a foolproof way to make sure she took some money home from the casinos...
She bought herself a nice leather purse. Then she went to the office supply store and bought a small, heavy cash box with a heavy duty lock on it that fit perfectly into the purse. Whenever we went and played, she'd cash out once she doubled the $20 she put into the machine (cashing out at $40). One $20 bill then went back into the machine and the other $20+ went through the money slot in the top of the cash box (and the key to unlock it was purposely left at home). I was really amazed at how well her system worked. Once the 20's ran out and we'd gone home, she'd open the cash box at her house to discover she still have at least half of her original bank roll. Until one night when she was gone to the ladies room alittle too long and I started to worry. I found her outside huffing and puffing with a really BIG rock attempting to smash open the cash box....she didn't want to go home yet!
Amazingly, that cash box did not break open and today we still laugh at all the dents in it! And yes, it is still her system for not coming home empty handed.