The Pardeys use them at anchor and instructions on how to make them are found on their DVDs. They use a box-type with a flapper valve, presumably so that they can be folded flat for stowing, but the rigging method seems identical to SmartCaptain's. Needless to say, they were homemade...the Pardeys don't like to buy what they can make!
Frankly, they seemed like a pretty good idea. Some anchorages that are otherwise safe and secure can get very sloppy. Also, I suppose deploying this device could fall under "chafe gear" because a boat that isn't rolling over 40 degree arcs is less likely to chafe. I would use this plus a riding sail.