Cleaning tips (eg item 4 here) often suggest mixing vinegar with baking soda to shift limescale and other stubborn stains. Lemon juice + baking soda is another common one.
Is there any rationale for doing this? Surely you want the acid to do its job on the limescale, and by adding baking soda you are just going to neutralise the acid before it has a chance to react with the limescale: acid + base = neutral salt plus water. What’s the dope?
This has been debunked before. Here’s one website I found that agrees with you.This combination may be effective with mildly clogged drains because of the foaming that occurs when vinegar and baking soda are mixed. And I think that foaming convinces people that it’s a general purpose cleaning mixture. On top of that people often have the ingredients handy to mix and try out, and lot of stains may come clean just from putting the effort in to scrub them.
It’s fun science. My grandkids love it. What’s not to love?
The fact that it doesn’t work? :smack:
Why do people recommend vinegar + baking soda as a cleaner?
Because they’re douches.
We use baking soda as a cleaner, but not mixed with anything. On a damp paper town it cleans by virtue of being a mild abrasive. Cleans baked on food spots from baking dishes and the like. Will also do an excellent job with bug bits on your windshield.
Maybe sodium acetate has some cleaning-enhancing properties but I’m not aware of any. I suspect people just like the bubbles.
Someone give Sicks Ate his trophy. 
Yep, if it bubbles, it must be a cleaner!
Both baking soda and vinegar have uses as cleaners, but not together as they neutralize each other.
I have had some success in dealing with problem drains using them, but that’s due to their expanding foam action which can dislodge some types of minor clogs sufficiently for ample running water to clear the pipe. That’s also why plungers can work - they can disrupt a minor clog. None of the above will deal with hair clogs, or clots of grease. Those require either mechanically clearing the pipes or much stronger chemicals.
I don’t usually see vinegar + baking soda to clean stuff. I see (and use) vinegar a lot, because it TOTALLY works. I see baking soda some - as a mild abrasive like **GaryM **says.
I think Buzzfeed has it wrong in the linked article. Vinegar and baking soda in a bag isn’t what’s normally prescribed for cleaning a shower head. I Googled “clean shower head” and all of the results were for cleaning the shower head using a bag of plain vinegar. No baking soda.
This article from Better Homes & Gardens starts off with the bag-of-vinegar method. Then when that doesn’t work for ya, it suggests taking the shower head down and scrubbing it - with a toothbrush and JUST vinegar, even though the image has vinegar and baking soda. Further down, when your shower head STILL isn’t clean, it suggests adding baking soda to vinegar before letting it soak. Not to remove the lime scales at this point, but "The natural abrasive will help release clogged passages. " so I think they’re seeing it as a bubbly way to get up into the shower head holes.
Anyway, I don’t see vinegar + baking soda a whole lot (yes I do see it for clearing clogs in a drain) but I do see mistakes and lazy reporting on Buzzfeed a whole lot.
Don’t discount the fun.
I have a Ph.D. in chemistry… so I was incredible surprised when I once had a plugged garbage disposal and a concoction of NaHCO3 and CH3COOH worked to clear it! I think the key was getting it in there fast and having the bubbles form near the plug, but I still to this day can’t figure out rationally how it helped when nothing else did. I tried it as the last step before Drano.
If you have a garburetor, a good way to clear a grease clog if it’s not fully blocking (i.e. sink drains very slowly) is to put very hot water in the sink, then force it through the pipes using the garburetor pressure. This will get the hot water down to the clog before it cools, where it will start loosening the grease. Repeat until clear. No chemicals necessary.
If you wait until the clog is full and no water can pass, it’s time for more extreme methods.