How about the natural way!
More Natural Ways to Clean Brass
Who knew cleaning brass could be so easy? There are just so many ways to do it safely and naturally without the use of scary chemicals that oftentimes strip away the top layer of metal. That stripping can eventually cause the intricacies of your brass to lose definition. The method outlined above is just my own personal preference. If you are curious about other methods, just have a look down here. The secret ingredient to all of these household brass cleaners is a weak acid with a pH somewhere in the area of 3 to 4. For all of these methods, rinse well and buff with a soft clean cloth or micro fiber cloth.
Ketchup! Yeah, baby. I'm talkin' about good ol' Sauce Americana. Sounds too good to be true, you say? Oh, yeah. I know. But really, just smear some ketchup all over your dirty brass, let it sit for a few minutes, and wash it off.
Worcestershire sauce. It just keeps getting better. Same as with the ketchup: wipe it on, let the acidity of the stuff work its magic, wash it off, and voila! Clean brass. Just be sure to rinse it off really well. It might take a couple of tries.
White vinegar and salt. Is there nothing vinegar can't do? Pour vinegar over your brass and then sprinkle it with salt. It's supposed to work great. Vinegar can also be used at full strength. Wet a soft cloth with it and wipe down the brass.
Yogurt. The lactic acid does the trick. Use a spatula to coat your brass in yogurt. Let it sit long enough for the yogurt to dry, and then buff it off with a soft dry cloth. Rinse the heck out of it. Turns out dairy products stink when they sit out too long.
Milk and water. Speaking of lactic acid, you can simmer your tarnished brass in a 50/50 solution of milk and water. Simmering times will vary depending on the extent of tarnish. Again, make sure to rinse it off really well, as rotten milk stinks.
More lemons (or limes). If the piece of brass being polished is not very intricate, it works well to simply cut a lemon or lime in half, sprinkle some salt or baking soda on the sliced end, and rub the brass with it. You may need to reapply the salt/soda. Rub with the grain of the metal.