Combine the juice of half a lemon with a teaspoon of baking soda and stir until it becomes a paste. Apply the paste with a soft cloth. If the tarnish is heavy, let the piece sit with the paste on it for 30 minutes. Rinse with warm water and dry.

How do you clean and polish old brass?

Quote from the video:
Quote from Youtube video: Before attempting to clean it. Step 2 clean unlocker brass with hot soapy water and a soft cotton cloth wearing rubber gloves to protect your hands dampen the cloth wipe down your brass. And then dry