Before cleaning any brass item, first determine whether it is brass plated or solid brass. To do this, hold a magnet against the surface of the brass fixture. If you feel a pull, the item is brass plated. If not, the item is brass and you will have to use another method to clean it. Brass-plated items have several layers of brass placed on their surface that can be removed with an overly abrasive cleaning method. Make sure to use soft abrasives such as baking soda and soft-bristled brushes to prevent scratches in the brass item.
Fill a bowl full of warm water and add a few drops of mild liquid dishwasher detergent.
Dip a clean cloth in the solution and wring most of it out.
Rub the surface of the brass fixture until most of the grime has been removed. Dip and wring the cloth again as needed.
Mix 2 tbs. of lemon juice with 2 tsp of vinegar if your brass-plated fixtures are still dirty.
Add just enough baking soda to make a paste.
Use a clean cloth or a soft-bristled brush to rub the mixture into the brass fixture and remove the grime. The baking soda will act as a mild abrasive, so do not brush too vigorously or you could remove the brass plating.
Rinse the brass fixture with clear water and dry it completely with a clean and dry cloth.