I have wondered the same thing. I live in the mountains and we have rocky terrain no way I can get rid of all the rock even when I pick them up the ground just makes more. Thankfully never have had bumble foot in any of my water fowl and only in 2 chickens up till this year when 4 of my Salmon...
Good thread because I have wrapped many a chicken foot but never had to do a duck yet. Always thought I would make a shoe first cut out of heavy cardboard or plastic container size of web wrap in tape then lay the foot on top then wrap because the foot would be flat on the shoe already.