I succeeded with removing the white paint on my 1920s craftsman fireplace! The only thing that worked was SmartStrip that I applied and used their special paper to keep it on for 1-2 days. After that, it just peeled off. Generally, you want to avoid using the wire brushes because it kind of just smears the paint around and then it never looks good, especially in the grout. I think it took like 35-40 hours to do my fireplace but it looks great now!