Gritty window streaks and vinyl railings

We bought a brick house with vinyl railings. They are covered with a grit that I tried bar keepers friend, Brillo pads, and dish soap. Only the Brillo, lightly scrubed, removed it but it took 15 minutes for a 6" section of rail. It would take weeks to clean everything. I also have this grit on my front windows. I had a window cleaning company clean my windows, but they don't clean off what they called masonry grit. Any suggestions?