A woman quit smoking by writing a $10,000 check to a friend, to be donated to the KKK if she smoked, leveraging a highly aversive consequence.

“So, what she did is she wrote a $10,000 check and gave it to her friend and said, "If you catch me smoking, I want you to donate this check to the KKK, which to her was the most aversive thing that could ever happen with her money."”