I use lacquer thinner to clean the block and bearings because it works the best for cleaning carbon deposits IMO but follow up with denatured alcohol. Laquer thinner is a very harsh chemical so it is only to be used on metal as it will melt some plastics and dry out rubber. If you can't get these chemicals then don't bother cleaning as you may end up with contamination with anything else. Just keep in mind that you are dealing with a micro motor. Even the smallest mistake could destroy your engine.