I started with a brass bristle brush (suede) and have gone to the stainless brush, little larger than a toothbrush. I don't "brush" as much as I push it against the strike point and move it back and forth, hoping the bristles puncture the felt a little. I don't like to see little wisps of felt on the hammers when I'm done, which is what you get if you just "brush" across the top. It does work well, but how long it lasts I'm not sure. Haven't been doing it that long. Paul McCloud San Diego
This PTG archive page provided courtesy of Moy Piano Service, LLC