You say Scotchbrite and I immediately think of the pads on the wheels for the diegrinder. (Same material as the pads although not as aggressive) Back about 10 or so years ago GM did a study as to why they were having so many lower end issues. (Bearings and such) most of the lower end failures had a intake revealed and Scotchbrite pads were used for gasket surface cleaning. Immediately, Bristle Disc's were designed and recommended.