Interesting and simple. Reminds me of snow goose hunters using white flags and shopping bags staked to the ground to increase the size of their decoy spread. Laundry detergent bottles work well with a little prep work too-cut a flap to open out of the bottom(simulates a tail) and paint to match your targeted goose species. Saves a lot of money if you want to set up 100+ decoys. Either spend $6-$25 per decoy times 100, or buy 5-6 of those expensive dekes and raid your wife's/mother's/sister's empty detergent bottles and add $15 total worth of Krylon.
The cow decoy looks interesting too. Something I wouldn't have thought of.