If the engine is out, I'd spray down with Gunk(in spray can), let it sit, and then use a high pressure washer to clean it off. Steam cleaner actually, if you have access to one.

Then if you need to you can repaint.....I know more work.....but do it while its out!!

 

dude for get that shyt, i washed my motor and my altinator and fuel pump relay went out [:@][:@][:@]pos...
never doing that shyt again.

 

did it short out?hope you didn't just pour it to the engine?