I get mine here from the states from people that make them.
Louise's Country Closet
They say "chicken" but I've already emailed her and asked directly, to make sure she has them large enough for geese, and she does. She said that the chicken diapers can also be used for ducks, as long as you...
I don't have it yet. That's why I don't have a diapered goose inside yet. But I'm getting sebastopol geese eggs to hatch very soon, and I'm seriously thinking about raising one as a house goose!