In my prior post, I did not mean to condone the use of *high pressure* blasting streams of water. I personally use an engine degreaser and a thorough rinsing.
By the way, if you can find a product made by Gunk called “Steam” engine degreaser, it is EXCELLENT. It comes in a black can, and it cuts through the muck much better than any other product. It is a bit more expensive than the others, but well worth it. I used to get it at AutoZone or Kragen, but I have not seen it for almost a year. Perhaps the State of California has declared this stuff as verboten. Sad.