For cleaning parts I use an SOS pad. Takes everything off and will actually polish the metal parts but will not affect the cast aluminum castings. For bearings, well I usually don't clean them. R/C Bearings.com can supply a set of bearings for just about any engine for around 20.00 shipped so to me it makes sense to just throw in a new set whenever I have an engine apart. If the crank has any rust I use a scotch brite pad that comes with a mandrel so It can be put on a drill.