Soak the wool for about half an hour in a basin of very warm water with a bit of Dawn dish soap. Move it into another basin filled with lukewarm water to rinse. Allow it to soak for half an hour and then pour the water off. If the water is very dirty, rinse again. You can repeat this until the rinse water stays clean. Remove the wool from the water and press out (don't wring) excess water. Lay the wool on a mesh surface or place it loosely into large mesh bags to air dry.