I mounted this very large goose and thought I had got all the fat & de-greased it well (not my first one) but after mounting and positioning. When I came back after several days of drying my wife noticed grease spots when she was grooming the feathers. We have tried the oil soaking pebbles/dust which we thought worked. She went to clean it up again and found another spot. Short of tearing it apart which I have never done and don't know if it can be done. What else can I do?