I started yesterday.
I'm going to to try to keep it up all 30 days without missing a day. It has been an effective way in the past of getting me back into to the habit of exercising regularly. How it works is there are 3 workouts: Level 1, Level 2, and Level 3. You do each workout for 10 days starting with Level 1. I don't know about the losing 20 pounds thing, but they are good, challenging workouts for beginners or if you haven't worked out in awhile, if memory serves.
I bought mine a while ago, but all 3 workouts are currently available on the BeFit Youtube channel if you are interested. Not sure how long they will be available there, but there are lots of other workouts, too.