I stay away from degreasers because they oxidize various surrfaces and leave powdery residue. I just use water and hand wipe everywhere I can get my hand into...and occasionally wipe on some silicone to various parts to make them a little extra clean (brake master cyl, radiator/intercooler hoses,fuse box, power steering res. etc...). I don't like my engine bay to look overly new and shiny, just clean and simple.