I'm familiar with two kinds of ball washers. In the first, you put your ball in a hole and then ram the washer rod up and down so that hard bristles and soapy water will clean your ball. In the second you put your ball(s) in a hole in the top of the machine and turn a crank so that the ball(s) rub against the bristles and through the soapy water.

Both would seem to stretch and hurt.