Better yet spray the whole bike especially the rims with silicone spray, it won't harm anything. Just spray it and leave it. My skunk is going on 13yrs now and doesn't have a single spot of rust, mind you it's in the garage most of the times though.
You should soak some rags with oil and shove them at the end of the exhaust pipes and another where the intake is. This will stop moister from entering the cylinders. Just don't forget they are there when it's time to ride.