Do you mean something like an artificial knee? If so, there is a need suction out cartilege scraps, clots, bone bits and dust, crystallized proteins...anything that will produce inflammation during the healing process. After cleaning, it's a perfect time to inspect ligament attachment alignment and integrity in the surrounding area. If there was a lot of bone destruction in the process, there are new materials available that provide "scafolding" platforms for the formation of new bone from osteoplasts.
If you are asking about cleaning the implant before it is used, then it is basically anything that has come into contact with the surface of the implant. Some of these things would be buffing compound, blast cleaning compound, marker, penetrant fluid, oils and grease from hands, and any air borne contaminates.