Super easy DIY copper and brass cleaner. 6 TBS salt, 6 TBS flour, and several TBS white vinegar. Mix flour and salt then add TBS's vinegar until you have a paste. Rub on with a soft cloth then rinse and dry. Ta-Da! Clean copper and brass without harsh chemicals!
13 Superb Ways to Make Old Things Look As Good As New
Cleaning copper/brass: Mix one teaspoon salt, one tablespoon flour and enough vinegar to make a thick paste. Rub paste on surface and let dry completely. Rinse in warm soapy water, buff with clean soft cloth. [This worked like a charm on my old and very dirty vessel sink/bucket.]