I, too, have a weakness for the sight of a new-looking engine and engine bay. Given the nightmare stories of those who spend days trying to track down "electrical grimlins," I recommend resisting any temptation to introduce water --especially from a hose-- into an engine compartment. (Older, 1970's pre-fuel-injection cars seem tougher in this regard.)

I have found moderate success with the combination of old rags --or good paper towels-- and a mild cleaner (sprayed onto the rags). It does require a good bit of patience and elbow grease, and, admittedly, MANY have used the hose approach with no grimlins.