I will NEVER spray water on an engine again, especially an on expensive GN engine. Many years ago, when i first got my GN, I was at a car wash and since they offered engine steam cleaning, I decided to have it cleaned and silicone dressed. I was probably 21 and dumb at the time.
The engine looked nice and shiny, but after that wash, i had nothing but problems and the engine started running like crap- it hesitated alot. It probably took months for all the water to evaporate. I was so upset that I had it steam cleaned. But i thought it was safe.
I would just take a rag and some Simple Green or a harmless cleaner and gently hand clean any areas and dry her down. Then you can spray a natural protectant on the rubber and plastic parts. I forgot to mention that after awhile that silicone dressing started to peel off of all the hoses, rubber and plastic. - what a mess.
i read alot of car detailing books and they always show pics of engine detailing, but they secure delicate engine parts with towels or plastic bags.
Everything in my engine is delicate so my advice to you is to keep water out of your GN engine, especially away from all the sensors- MAF, map. etc, spark plugs, coil pack, etc. Believe me, spraying water on a GN engine is not something smart and safe to do.
Good luck
PS: just take a rag and wipe her down really good and make sure you dry off any moisture.