I think those would make a killer Canada Goose load. I got some cheap as well and if no one ever wants them I hunt with, I will use them in Canada for geese. I will use my IC choke and pattern one before I use it, but should be good on those 50 yard passing shots.
I personally would not waste those on ducks. No duck that I have ever hunted that can't be cleanly killed at ethical range with a #3 steel. If I miss, it is on me, not the shot.