Cleaning or preservation?....even a brass brush will mar a mirror finish, especially as it picks up rust....soak blade in kerosene or diesel to passivate and loosen rust....brush out of pits and resoak if red shows....you can use steel wool or even 1000-2000 grit sandpaper if truly bad, doing a crosshatch with both....finish with tripoli cutting compound and then red rouge....a power wheel helps but only if you can not let wheel snatch blade and throw through your head....preservation is easy....keep clean and keep coated with wax of some sort which does not evaporate, gum up, and turn acidic, and do not ignore....and especially never ignore while in moisture magnet absorbing sheath....even plastics sweat moisture....ask shotgunners who left plastic shells in chambers....