I ran across this on the net last year...i've been doing it ever since...it is crazy how easy it is after you get the first cleaning done....every couple of months I spend 15 minutes and it looks brand new... the web link is
http://www.1017.org/nsx/Enginetrick/EngineTrick.htm
I did almost exactly per that site, but used simple green starting out, then the foaming tire spray that was on sale that week at the local autozone.....just make sure you cover everything up that you do not want water coming in contact with...but was so easy, esp now that it is just maintaining it....