I breast/leg all ducks and geese the day of hunting...
I will rinse them clean, and then vacuum seal and freeze all meat for a minimum of 10 days. I read that all wild game should be frozen for 10 days before consumption, so I have been doing it for years and have never been sick/poopy.
I then soak in a mild salt water solution overnight while thawing and then cook. I either make kabobs, nuggets, or goose breast steak wrapped in bacon.
I have heard of ageing ducks/geese, but have never done it and never not liked the taste...