A can of Brasso and some Q-tips. Unplug all AC plugs and saturate the blades with the first set of Q-tips. Let them dry overnight.
Rub off the dried Brasso until they're slick and shiny. The second set of Q-tips will be black, reflecting oxidiation. Repeat every 6 months.
Rub off the dried Brasso until they're slick and shiny. The second set of Q-tips will be black, reflecting oxidiation. Repeat every 6 months.