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 an intake revealed and Scotchbrite pads were used for gasket surface cleaning. Immediately, Bristle Disc's were designed and recommended.