I am currently trying to remove stains from a new porcelain tile installation. The porcelain tile is unglazed, and more or less "open" . It is in a bathroom in a commercial building. The staining appears to be coming from the grout. The grout is black and so are the stains. The tiles were sealed prior to installation with Miracle Sealants "Porous Plus". The grout is laticrete perma color. We have tried cleaning it with our usual stone cleaner, Viper Venom by Bridgpoint. No results. Then we tried acetone which yielded next to no results. The we tried Aldon's Premium Stripper (solvent based). The we tried an epoxy grout film remopver. No results. None of these chemicals have impacted these stains. The floor will have to be torn out unless I find a solution. Attached are some photos of the floor. Any ideas?