Does it hurt a magnet to shave it a bit to fit a can? I was going to do the SB mod but then saw a brush that had a Braun motor and figured it had to be better than the crest motor. Unfortunately the Braun can is longer and so the magnets are longer. The RS armiture is too short for the Braun can and the Braun magnets are too long for the SB can. I was planning on shaving the Braun magnets to fit in the RS motor, will this hurt the magnets?