If you're thinking about using vinegar to remove concrete sealer, you're going to be disappointed.
Vinegar contains between 5% and 8% acetic acid, the rest is mostly water. Most all concrete sealers these days are designed to be RESISTANT to acids and acidic based products.
Now, to what extent your concrete sealer will resist the acid in vinegar depends on what kind of sealer you have on your concrete.
If you have an acrylic solvent based or water based sealer, these are the least resistant to acids. But they're still designed to resist them.
Trying to strip off an acrylic concrete sealer with vinegar would be tedious task at best.
If you have an epoxy, urethane or polyaspartic concrete sealer, you might as well forget it. These sealers (really coatings) are much higher quality than acrylics and vinegar may dull the finish but it won't remove them.
Below you'll see a typical data sheet of an acrylic concrete sealer. The yellow highlighted areas clearly say it's resistant to acid.
Most all manufactures of concrete sealers (at least to my knowledge) have this in their data sheets.
You'll be better off using a chemical stripper that's designed to remove concrete sealer than you would be using vinegar.
If you use vinegar at full strength and it comes in direct contact with the concrete, it will etch the surface causing it to look dull or even slightly pitted.
Now, the extent of the damage will be dependent on how long you leave it on the concrete. But as soon as you pour or wipe on the vinegar, the acetic acid will react (fizz) with the cement paste and etch it.
If you've got concrete counter tops or polished concrete floors, vinegar will dull the surface and damage the finish.
There's a few different methods you can try to remove concrete sealer. All these are better than using vinegar.
1. Pressure washing using a surface cleaner - The rotating action combined with the water pressure works very good for removing and stripping off old, white concrete sealer.
2. Chemical strippers - You spray, roll, or brush on these and let them dwell for a while. Then pressure wash or scrape away the concrete sealer. May take a couple applications.
3. Sand blast, Soda blast, or Wet media blast - All these will completely remove the concrete sealer. They're kind of messy but very good at stripping off sealer. You'll have to hire someone to do this.
It's best not to use vinegar to remove concrete sealer.
Vinegar is more likely to dull or etch the sealed concrete surface rather than strip off the sealer.
Use a product formulated to strip off concrete sealer or try Xylene. Make sure to wear the proper protection if you do.