Spray it down with greased lightning and let it sit for a few minutes, and then power wash it with a high pressure washer (if you don't have one, go to the local car wash). After that, coat it with baby oil. Any dust, pollen, grime... the baby oil will catch it and it will wash right off easiely. Reapply the oil to repeat the processes. Baby oil on a rag is much cheaper than spraying can after can of silicon! Save the silicon for the tires on your trailer so they don't dry-rot. Trust me, the Greased Lightning works wonders on my 170 Bass for stains and marks, and it does'nt harm it. Just let it set for a minute before it dries up. Your local car wash sprayer has the power to wash the grime away. I would't suggest spraying the intstrument panel but the rest of the boat will look like new. Also a tip for you, I spray the motor from top to bottom with WD-40. I guess it prevents corrosion, at least I think it should. Hope that helps. Happy boating!