There are some professionally applied epoxies that will work, however, I wouldn't call them "paint". I had to grind some of that stuff off a Corian countertop and I lost my butt on that job. Brutal.

Good industrial epoxy applicator companies will consider your job too small to do. You’d have to be getting the rest of the home done at the same time. Any of the new fly by night epoxy coaters are guaranteed failure and water damage. There’s a huge number of issues with them.

Id skip it and look into #microcement