Broken windshield wiper motor

To the caller trying to determine why his windshield wipers aren’t working and in the meantime is using a towel on rainy days, there’s another “meantime” suggestion that i’ve seen on TV, but never tried myself: keep a fresh, raw potato in the car. If it rains, cut the potato and rub the cut side on the windshield. It’s supposed to cause water to sheet off without obscuring vision. But, of course, only an interim measure.