I use them frequently. Soak them in water to untie. Lay them out on a flat board and nail them down to stretch and flatten them. They will dry hard and shrink a little. Take out nails and sand them smooth and flat. Sometimes I do this process more than once. As Pat says, they are quite thick and uneven, so the thinning is necessary. Once thinned out, wet again to use on the bow. They are usually not long enough, so I overlap at the handle.
Russ