You can clean the interior barrel, cylinder, and frame of the 642 like you would clean any other revolver. You should avoid harsh solvents and abrasives on the exterior as it is clearcoated. Many swear by CLP to clean and lube their 642s. Don't bother with the carbon rings on the cylinder face, they will only return. Wipe it dry and give it a coat of Renaissance Wax periodically. It will preserve the finish. Mine is a coupla years old....