The mix is only OK if the brine has no undissolved salt crystals in it. Wherever a grain of salt in vinegar lays on the brass, a hole will be made by the HCL.
Diluted ammonia is a little better.
You can scrub with fine steel wool and windex and get a satin polish to the metal.
Casey

That happened to me once when I let an item soak too long in the vinegar-salt mixture.

Brass is an alloy of primarily copper and zinc. Cleaning it with an acid solution causes some of the metals to leach out, and a layer of copper is redeposited. I've read that polishing with Brasso (which is somewhat abrasive) will remove the superficial copper coating and restore the new brass color. I haven't actually tried this, but it sounds reasonable to me.

If left uncoated, the brass will eventually darken, or you can use ammonia fuming or a commercial antiquing solution to hasten the process.

P.S. I've read that soaking brass in ammonia can weaken it and cause stress cracks - I don't know if it's true.

Here is a link that might be useful: How to add patina to brass

The acid attacks the zinc first leaving the surface mostly copper. Almost any abrasive will remove the copper and get you back to brass color. Use a tooth brush to get into the corners.
Getting back to an "Antique" brass color is more difficult. I tried an "Antiqing" solution one time and was less than impressed with the results.

I "Antiqued" some Bronze switchplates by removing the manufacturers finish with scotchbrite. The heated the oven to 500 deg (that's as high as it would go) , placed the switchplates on the oven rack , turned the oven off and went to bed. The next morning I had antique switch plates. Looked a lot better than that black paint they put on bronze and call Antique. Don't know if this would work on brass or not.

That lock looks like an old skeleton key lock my parents used to have on a house in Maine. They would go to the five and 10 cent store and buy a new key. The store had half a dozen different shapes and they would just pick out the one that looked like there's and it would work. The door was rarely locked so the key tended to get lost.

Cleaning brass with vinegar should work just fine. You could also use concentrated lemon juice since the citric acid really gets the stains off of it and gives it a new shine. Same thing goes with cleaning with vinegar. http://www.cleaningwithvinegar.net

Here is a link that might be useful: cleaning with vinegar

Just make sure the hardware is solid brass.

Acid cleaning of plated brass revels the underlying metal VERY quickly.

I recently soaked what I believe is brass hardware from an old dresser in apple cider vinegar and salt. When I removed it from the solution some of the handles have chunks missing and splits in some areas. Just painted my first dresser and last step was hardware and I'm afraid they are ruined now. Any suggestions on how to repair or what I could do to make the handles still usable and paintable?

Bar Keepers Friend - it's cheap and easy to use, come in liquid and powder. Why ruin brass when cleansers made for metals are available??? If it's really tarnished Simichrome from Germany works.

I have used Spic-N-Span and ammonia for many decades now to remove heavy oxidation. Works well with no apparent damage. Did a tuba in the bathtub one time. As I recall the method came from a restoration class at the Smithsonian. You still need to do a light polishing at the end for a shiny finish.

If parts are falling apart after a soak in acetic acid (vinegar) you've probably got parts that were patched with something that dissolved and fell out when soaked. Repatching or replacing are your options at this point; I'd choose the latter.

Thank you guys for your responses! I think rwiegand is right. They must have been patched together with something. Or the handle at least wrapped in another metal as it is the only part that was damaged. Curious though- how would you repatch metal? Also trying to add A photo so you can see exactly what I'm talking about when I say damaged!

Looks like defects in the casting. Use bondo or an epoxy paste to fill, sand smooth, then replate. I'd talk to your plating guy about how to prep the surface. Unless you're really attached to those pulls I'm not sure it's worth the effort. Perhaps epoxy filled with fine brass dust would give an acceptable appearance.