German silver is not pure silver. It's actually an alloy comprised of varying ratios of nickel, copper and zinc; and is called nickel silver, paktong silver, or alpacca silver. Proper cleaning can be a challenge, as many cleaning products intended for use on pure silver will not necessarily have the same effect on German silver. Precious metals cleaning plates will generally clean both silver and German silver surfaces, but check the product's accompanying manual for confirmation.
Wash the item in warm water and mild dish soap to remove dirt, dust and oils. Rinse it well, and then gently blot the water from the item's surface with a soft, static-free, lint-free drying cloth.
Place a precious metals cleaning plate in a sink or bathtub filled with hot water. Follow the written instructions that came with your cleaning plate in order to add to the hot water the appropriate amount of activator either sold with, or intended to accompany, your specific brand of cleaning plate.
Place the tarnished item in the hot water so it is in contact with the precious metals cleaning plate. Allow the tarnish to dissolve, and transfer to the cleaning plate. The time necessary for this will vary, depending on the amount of tarnish.
Rinse the item with warm water and then gently blot the water from the item's surface with a soft, static-free, lint-free drying cloth.
Repeat steps 2 through 4 for heavy tarnish, but increase the amount of activator used. Check the instructions that came with your precious metals cleaning plate for that brand's recommendation.
Leave the item in a mixture of one part ammonia to three parts water--for the heaviest of stains--for up to 30 minutes. Wearing a pair of gloves, remove the item from its bath and rinse it thoroughly with warm water. Then gently blot the water from the item's surface with a soft, static-free, lint-free drying cloth.
Polish the item. Be sure it has at least been rinsed with warm water and then allowed to dry completely. Gently buff the item with a Selvyt polishing cloth until it shines.