You'll do much better with a chemical stripper. _Way_ less work and less damage to the concrete.

@rwiegand Would chemical strippers be something like a citric acid solution? Those are the solutions that are like a gel and stick to the surface for an extended time period? Is there a brand you recommend?

@User I wanted to try soda blasting but the only vendor who can bring a sandblaster to my site uses glass beads and aluminum oxide. I was afraid those would be too abrasive?

A stripper with methylene chloride will be the fastest and most effective, but you probably can't buy it any more in CA. Any gel type commercial stripper should work. Citrustrip is safe and works, albeit slowly. Glop on a thick layer and then wrap it with plastic wrap and let it sit overnight. , scrub it off with water and a stiff scrub brush. It might take two applications if there are a lot of layers.

@rwiegand The common complaints I read on reviews of Citrustrip is that it is very difficult to remove, and on some objects it actually moves the paint deep into the surface of wood and permanently stains it in a way that cannot be removed. Maybe for concrete that is not a problem since I think a white stain would disappear into the concrete's natural color.

Is there a way I could just make this myself from citric acid and some kind of sticky gel? I could use a food starch with a strong 3% citric acid solution mixed in?

Citristrip has no citric acid in it. I've never heard of stripping paint with citric acid. No idea how or why it would work from a chemistry POV. Lye (sodium hydroxide) works, albeit with some significant hazard if you don't know how to handle it safely. There are other commercial strippers you can get at the big box stores.

As to residue or staining, as always, experiment on an out-of-the-way surface to be sure you'll be happy with the result before doing the whole thing. It's the only way to be sure.

Here's what's in Citristrip per the SDS. Feel free to try and replicate it. For me life is too short to engage in that kind of chemistry experiment to save 20 bucks.

Benzenemethanol {Benzyl alcohol}

Diethylene glycol monobutyl ether {2-(2-Butoxyethoxy)ethanol {(a glycol ether)}

2-(2-Aminoethoxy) ethanol

Hydrotreated light distillate (petroleum, mineral spirits)

Alcohol ethoxylate (Alcohols, C9-11, Ethoxylated) Terpinolene
d-Limonene

@rwiegand Is there a simple way to remove Citrustrip after it has been one for 45+ minutes? Could I just power wash it off on the lawn?