WD-40 bad for rubber. Shortens the lifespan. Something silicone based will not harm the rubber. As a rule organic based will.
Is there something magically ******** about the way the SHO electrics were designed and implemented? **** take a yamaha watercraft. Nothing unusual looking about its electrics. No extreme measures that look particularly different than what's under the hood of a car. Yet you are instructed to wash the whole engine compartment out with a hose to clean it preferably after every ride.
If water is hurting your engine then your wiring is just aged and getting messed up and it's going to be prone to flaky problems anyways. Best to know if your motor's wiring is in good shape so you are at least aware that some electrical tracing might be in your SHO repair future. Besides, problems from spraying water on the engine tend to dry up when you let the motor dry up! That's why you clean a warmed up motor and run the thing immediately after and let it idle at fast speed until all the water evaporates!!!
I get sick of people saying no-no to spraying water on the motor of a SHO. I had a customer once, a very short lived customer who was a programmer for NASA up at Ames Research Center. He just thought he knew it all but he was a complete ******* idiot when it came to hardware and he didn't even know it. See, he had people at work to take care of the $50,000 workstations that he used. Anyways he bought a POS modem, lots of those in the consumer space back then, and just couldn't accept the fact that his problems lied there and blamed my COMMERCIAL grade equipment. He tried to tell me how much he knew because he was a hot **** programmer at NASA Ames. Funny, I've heard the same kind of cocky **** here from narrow minded types who need constant self-reassurance of their supposed greatness. Anyhow, the more this guy talked the more apparant it became of how little he knew about any of the hardware that was beginning to trickle down into the consumer space. Yup, because he was a big hotshot programmer on a cool SGI at NASA Ames Research Center and because his paycheck could finally buy his family some poorly chosen crap from Frys he thought he knew it all. Anyways he was one of those fools that I let my competitors have.