also know a guy that put his cylinder head in the dishwasher worked a treat .if you do, get up at 3am and do it or you will have your c**k chopped off!
Traditionally it would have been done in a degreasing tank with trichloroethylene or trichloroethane. I dont know what they use now that these chlorinated solvents are no longer acceptable or even available. I see the point about rinsing with water so that rules the dishwaher out as well.
Use paraffin to get it clean then finish off with white spirit as suggested by nedmin or with the thinners for the paint you are presumably going to apply.
Had to remove oil from weathered galvanising before using epoxy. First tried washing up liquid - useless. Then tried concentrated International Super Cleaner - better but still greasy film. Wiped twice with acetone on paper towel - completely oil free - water did not bead on it.
I have used Acetone with no problems, keep up-wind, buy a lot more than you need, it's cheaper in bulk and keeps forever, very handy cleaning and degreasing fluid. Don't throw out used Acetone, put it in a container and let the crap separate out, drain off the clear portion and use it again.
.. as used in many professional applications but, although not restricted, it is difficult to get retail in any litigation driven state. Being less volatile it stays on the job longer. It is also less deleterious to painted surfaces. There is no personal danger unless you breathe it in vapour form excluding other air for quite a time.
Thank you all for time & assistance. The item is a turbo housing, with fans in place, and it's a v...o; therefore expensive to replace. Trichlorethylene used to be great but they found that if you put a rat in steel shoe box & forced it to breathe the fumes for four hours a day the rat suffered! How did our ancestors live long enough to reproduce?
I intend to try paraffin followed by white spirit.