For cleaning silver put the items in a bowl with a handful of washing soda and some aluminum foil cover the items with enough water to cover them. Make sure that all the silver is touching the foil at one place or another. Take the silver out and rinse in hot water and dry thoroughly.
IMPORTANT:- Do not use 'washing soda crystals', these react with the aluminum foil and give of noxious fumes. Use the powdered lime-scale remover (sometimes called water softener). This is generally sold for use with your washing machine