I feel the same way about shiny decoys, even though I cannot prove they have ever hurt a hunt when I use them. But, my way of fixing the problem, if there is one, is to buy a cheap can of flat black or charcoal gray spray paint. Hold the can about 2 to 3 feet away from the decoy and spray it so the paint mist from the can barely hits the decoy. This will take away the shine without discoloring the actual paint job on the decoy. Use just enough to take the shine off. Good Luck!!!!!!!