175 Brushes most of the time don't work like you think...Manual labor sometimes with wire brushes (harbor freight) or blue Carlisle nylon pole brushes back and fourth...I also like a black pad (ceramic and porcelain tile) for removal of like "swifter" films and more...Chemical doesn't typically melt away everything...I don't have all day to wait either! Especially on natural stones like "travertine" = White Pad or Hogs Hair pad with safe chemical on Natural Stone...I did use the malish brush recently on a look a like slate material with rough surfaces and it worked (helped)...Either way, it will be trial and error! Every job seems to be different!