At some stage you are going to have to replace your rotors so why not upgrade to rotors. Clarks wavey rotors are made from corrosion resistant steel, without the loss of performance even on the most arduous decent.
Clarks Wavey Rotor Features:
Rotor plus 6 'Torx' headed bolts
Buy Clarks Wavey Rotor from Chain Reaction Cycles, the world's largest online bicycle store.