Can't Get Expiry Options Plugin To Work

I want my coupon listings to delete when they expire, so I downloaded Marks Expiry Options plugin. In expiry options set up. I set it to coupon_expiry_date, then expiry_date, and a few others, but It would not delete the coupon listing. If anyone could tell which combination of Expiry Date Field, and where to add the date, Coupon Expiry Date, Expiry Date, or a different field, I would appreciate it. I need to get this working, or figure out why it is not working.