Downy balls automatically release fabric softener into a top-loading washing machine during the rinse cycle. Users place a predetermined amount of Downy fabric softener into the ball, close the ball, and drop it into the washing machine at the beginning of the wash cycle.
The Downy ball floats at the top of the washer until the spin cycle, when it is forcefully thrown against the side of the machine. This sudden event causes the ball's gasket to dislodge and its seal to open, spilling the contents of the ball. The empty ball then sinks, as the escaping fabric softener mixes with the water during the rinse cycle.