This probably won't be much of a hit with this crowd.....
Screener: "Ma'am, I also recommend you remove your shoes..."
Passenger: "You expect me to walk barefoot on these floors?"
Screener: "Oh, don't worry. You won't get our floors dirty."
(True story. This screener has amazing people skills and great sense of humor. The lady took his comment as intended and had a great laugh.)