Soap and water with a brush is all I have ever done. Hose down the bilge with WD40 or smiliar when done cleaning. It works very well. If you are only doing it once in a while then I would just give it a really good clean. I flush my motors for 15 min each after a trip into the salt. While the motors are running I wash the deck and interior then the sides and trailer. Takes about 1 hour.