I just visited the owner of Car Care Specialties and he told me its completely fine to hose down the engine. Here is an article that he wrote on proper engine cleaning that may be very helpful: http://store.carcareonline.com/enginecleaning.aspx
He is a concourse judge/ contestant. He won 22/24 concourse competitions that he has entered. Give him a ring if you have any questions, I can't believe how helpful his convo with me was. I'll post pics of the process later. Time to clean!