A couple reasons… First, I see no mention of preservation. Second, unless you’re very experience in the proper fleshing of waterfowl, you’re not getting all of the fat and tissue off of the skin and out of the wings by scraping. Third, if you were to throw a well mounted duck into the water, it will rot in time. Preserved skin is not waterproof, and it just can’t tolerate being wet like that, then being tossed around in a decoy bag. I just don’t seeing it working well, and I’d hate for you to spend a lot of time on something that's bound to fail.