So I decided to try my wool mitt today to wash my car since I had not used it since discovering the GS. I finish washing and drying, I inspect the car with the halogens, and there it was on the lower panel of the passenger side, a series of scratches about 10-12 inches long :wall. The car was very dirty and even though I used two buckets and rinsed the wool mitt often, it was not enough to keep from marring the paint. I ended up having to hit that part with the orange pad and SFX 2. If I ever had a doubt about the GS, I don't now for sure. I don't think this would have happened with the GS because it rinses out so well. Something must have gotten caught in that mitten, which was not released even after rinsing it and scrubbing it on the grit guard. Had not had swirls or scratches since discovering the Lowes GS.