Are those car wash mitts any good or do they scratch the car?

I want to buy one. If I do, I'll rinse it often so that dirt doesn't build up on it. I mainly want to use it in cold weather when rinsing the car but not wanting to freeze my hand. I'll wear a kitchen rubber glove inside such mitt. However, if you think those mitts scratch the car, I'll have to rethink the car rinsing strategy. Thanks.