I try to wash ans scrub the rods on my sharp maker after each use. I am useing comet and a scrub brush with warm water. After I finish cleannig; there seems to be metal left on the rods. I have tried soft and rough brissle brushes . Am I expecting too much. Are my results normal ? Am I going about this the right way? Am I cleanning it more than I should ? Any suggestions will be helpfull. The blades I am sharpening are D-2 and a few ausa8