Yeah, knowing about those hinges are a life saver.
But on the tennis ball, I just use my 6" sill squeegee and throw a towel on it. I’m always carrying the 6" so it’s always ready to go.
Heck I even use it to put up Christmas lights on a tall tree I have in the front yard: flip the channel backwards and it’ll hold the string good enough to get the tree decorated.
FREE TENNIS BALL Giveaway YEAH … Great tip