Question is, why do you have rust on your cables? Has the bike been sitting for a while? Are you near the ocean? Are you in the North where they might use salt on the roads?
The whole point here is the condition of your cables. If there is corrosion on the outside of the cables, there maybe more serious corrosion at the core strands. If the corrosion you can see and get to is pretty bad, you might be better off replacing the cable particularly the clutch. Bad news if that breaks on you. At least do a real thorough job of lubricating the cables inside of the jackets. I like to use an aggresive penetrating oil like Kroil liquid. Pretty confident that works its way into the strands.