Eco Housekeeping Tip #21: 1. Create a tightly wrapped ball out of wool yarn (you can start by wrapping yarn around your finger). 2. Once ball is the size of a tennis ball, tie it off (we use a crochet hook to loop the yarn through the ball). 3. Wash yarn ball(s) in a stocking with HOT water and then dry on hottest setting. The ball will begin felting. 4. After ball is dry, you are ready to use. Just throw in dryer with wet clothes. The more you use it, the better it gets!