Well I've used a cleaning solution called Simple Green. You have to dilude it before you use it. After you have mixed it just spray on the top section of your motor and cover the extremely dirty sections, let it sit for about 5 minutes then rinse it off well, used to work wonders for my old jeep after a day out in the mountains.
cool where do you get it just at advance or something? When spraying off the engine do you have to be super careful about anything or is it pretty water resistant
Kilgore has the cleanest engine bay on the face of the Earth. Maybe he will post some tips.
I use simple green, spray water with care (don't hose down important electrical stuff), then dress the rubber with your favorite stuff. I like 303 Aerospace Protectant as do many on SN but there is a Meguiars product that works good too (can't remember the name) ...