hHow clean is clean? I have scraped it with a a scraper, wire brushed the residue left sticking to the joint. There is still a thin layer of sticky black residue left from the wire brushing on parts....
I do have a couple of cans of non chlorinated brake cleaner from AutoZone around that can be used. It is water Dispersible with a good rinse after it dries. It has all ready been cleaned with Ausem Orange. the stuff will clean oiled motors if you use it that way