Why not throw a piece in to felt? The interfacing may create an interesting texture, you never know. Might end up kind of like the texture magic? If they can't be felted, maybe they could be sewn into Christmas ornaments or stockings. Maybe some house slipper with flannel inside. How about draft door stoppers? Remember those sewn to look like long wiener dogs that you laid at the back door to keep out the cold? (before weather striping)