Do Dryer Balls Really Work? (Test Results) .
Tennis balls are much louder than dryer balls when they bang against the walls of the dryer''s drum. The green or yellow dye from new dryer balls can transfer to your clothes. Old tennis balls are usually filthy and not an item you''d want rubbing against your clean clothes. Tennis balls are made of chemicals that are not designed to be heated in the dryer. How do you add essential oils to ...