Sorry Mc have to agree with NEO, I know you don't want to but splitting the cases is really the best thing to do. If you washed out a load of crap then there is still a load more smaller crap in there, just one small shaving will turn your nice rebuilt engine into a paper weight.
I watched a mate of mine, many years ago, take a large 5 gallon drum half fill it with paraffin drop his engine inside then shove his air line into the engine casing and bubble the thing clean, he left it for about 4 hours and pronounced it clean, 2 days later he seized it on the way to work.