Just read the instructions on a ProMar200 Latex paint can (scairey, huh!!!).
Under plaster it says: "Textured or swirl types and soft porous or powdery
plaster should be treated with a solution of one pint household vinegar in
one gallon of water. Repeat until the surface is hard. Rinse off with
plain water." What does that do and how???
CuriousCuz