"Put your money where your mouth is" is an old much-used saying. It's time to stop using it. Why? Because if you literally put your money where your mouth is you'll likely be licking a lot of germs. And cocaine. According to Time.com: "Studies show that a solid majority of U.S. bills are contaminated by cocaine. Drug traffickers often use coke-sullied hands to move cash, and many users roll bills into sniffing straws; the brushes and rollers in ATMs may distribute the nose candy through the rest of the money supply. Also found on bills: fecal matter. A 2002 report in the Southern Medical Journal showed found pathogens — including staphylococcus — on 94% of dollar bills tested. Paper money can reportedly carry more germs than a household toilet."
Money is dirty. Filthy. It has germs, cocaine and fecal matter on it. Fecal matter? Ew! You don't want to put money anywhere near your mouth. Maybe we should change that saying to "Put your money where your ass is."