It worked! I rented a 3500 psi pressure washer from Home Depot and it removed the paint from the patio. The paint was latex if I remember right. Epoxy would be difficult to remove but you could try it, it doesn't cost much to try. The washer removed 99+% of the concrete, and since we are going to put flagstone over the concrete that is sufficient. It's slow, we took over 6 hours to do a 450 SF patio, use the narrowest nozzle.