Modern pewter resists tarnish and needs only an occasional wash in soapy water. Rinse well and dry with a soft cloth. The tin and lead in old pewter may cause it to develop a brown tarnish. A washing soda solution may help remove this. Because of the lead content, do not eat or drink from old pewter utensils.
Commercial polishes are available for use on old or modern pewter. For modern pewter, you can make your own from pumice and water for a matt finish, or a powdered whiting and alcohol paste for shiny surfaces. Car polish can also be used for shiny surfaces.
Silver does not corrode in the accepted sense but is tarnished by hydrogen sulphide and other sulphur-containing gases. This can be removed by a standard silver polish. Alternatively, the reaction can be reversed, that is, the silver sulphide converted back to silver metal using the following procedure.
Put some hot water in an enamel or pyrex pan and add a few teaspoons of sodium bicarbonate (baking soda) to the water. Wrap the silver to be cleaned in aluminium foil. Leave a small opening in the foil and put the wrapped articles in the solution. Ensure the articles are completely covered by the solution and that no air bubbles are trapped inside the foil. This is to ensure proper cleaning. All the utensils must touch at some point. Depending on the degree of tarnishing, the articles will be cleaned in about one to five hours