[Spridgets] What to use to clean an engine for paint?

[David Booker]

OK - So it sounds like the lump's gotta come out so I can replace the throwout
bearing / clutch plate.  Since it's going to be out for a breath of fresh air
and sunshine - it would be a shame to put it back in there all nasty looking. 
What is the best thing to clean up an engine and get it ready to paint?  And
the nasty engine compartment while I'm at it...
 
David Booker
'71 Midget
Long Island