that may be where it came from originally.
I got it from a regular at a bar I used to work at in downtown Kansas City.
He would come in, spend several hours drinking and carousing, and then go home. (He lived catty corner across the street from the bar)
He would lay a twenty on his table then he would tell the wait staff, "Here's your tip. Every time my beer mug goes empty a dollar goes back in my pocket."
I very rarely saw his mug empty.