:rofl
Hit it with an orbital and it’ll be good as new, if not better since most dealerships swirl up their cars when they detail them anyway.
And the brush can and will cause clearcoat marring/swirling. I’ve seen it done first hand.
Go wash your car with the brush, park your car in the direct sunlight, and take a picture of the hood where the sun is reflecting off of it. If there are no swirls then you either got lucky or your camera/eyes are junky.