A simple way to lightly clean without having to do all that polishing,, line a large container with tin foil, shiny side up,,add about a cup full of the old fashioned Tide laundry detergent that comes in a box,, the one with out all those additives,, fill with warm water,,let soak about an hour or two then rinse and buff dry !! This should clean without removing all the signs of age !! You can do a lot quickly like this and no fear of damage !! Just make sure the soap is well dissolved before adding the silver !!