To clean pewter, wipe it with diluted dish soap, rinse it with water, and dry it thoroughly. If you wish to polish the pewter, use a commercial polish or a homemade alternative.
There are several types of pewter. Polished pewter is extremely shiny and benefits from regular polishing to maintain its appearance. Oxidized pewter, however, has a chemically darkened surface that does not tolerate polishing. Satin pewter has a dull surface. The best way to polish this type of pewter is to rub it with steel wool and a polishing scrub, according to Bob Vila.
To make a homemade satin pewter polishing scrub, combine 1/2 cup white flour, 1 cup white vinegar and 1 teaspoon table salt. Stir the mixture into a paste, and then rub it over the pewter with a steel wool pad using circular strokes. Wait 30 minutes, rinse the pewter with water, and dry it. To use this paste on polished pewter, omit the salt.
Another homemade pewter polishing solution is a mixture of boiling linseed oil and pulverized limestone. Coat the pewter in this mixture, rub it in with a rag, and then rinse the metal thoroughly. Do not leave this mixture on the pewter for an extended length of time.