I changed the spark plug on my '08 YZ450f, and I noticed there was some rust corrosion all around the metal base of the plug. I'm assuming the rubber boot for the spark plug cap was not properly pushed down and sealed, and moisture entered in the housing. After I removed the plug I noticed some of the corrosion stayed on the aluminum head where the plug seals to the engine. I tried to clean some off with a rag and a small tube to push the rag down the shaft. This was not very effective, although it did clean some of it up, and there wasn’t a lot to begin with. Is there some something I can use to clean this up, or is this something I should not be concerned with. Bike starts and runs fine. I just don't want the corrosion that's there to continue to corrode my new plugs. Also, I bought come electrical spark-plug sealant at the auto parts store. I used this to put around the boot of the spark plug cap to get a better seal.