We have found over the last several years that Poultice when combined with a High Alkaline Cleaner such as Aqua Mix Heavy Duty Tile & Grout Cleaner is an excellent problem solver for deep stained natural stone.
The poultice is mixed with the high alkaline cleaner and applied over the stain and then covered with plastic and perforated. This is then allowed to dwell for 24 hours and then removed. The success in removing deep stains is astounding. In the case of really deep ingrained stains a second application is sometimes required.
The method has been successfully used on really large areas such as the walls in the University of Westminster in Regent Street where the Marble walls were heavily soiled. This method was employed and as well as pulling the years of heavy soiling out it did so with no damage to the finish.
We were recently approached by a major cleaning company who had been called in to a problem with a residue transit wax on 380M2 of 600 x 600 Large Format Polished Porcelain tiles in a prestigious car showroom. We advised the usual methods of High Alkaline Cleaner, coupled with Sealing & Coating remover and even boosted by NanoScrub none of which would shift the ingrained wax. Eventually we did a test area using Aqua-Seal Poultice Plus Mixed with High Alkaline Cleaner and used in the method described above the results were amazing the wax was totally removed. We then suggested the tiles be given a final overall polish using a Porcelain polishing powder coupled with a Natural Hair Pad.
The finished result was stunning. It works on Granite, Marble, Travertine, Limestone, Terrazzo, Yorkstone, Flagstone, Pavers, Sandstone, Victorian Floors and now we know on Porcelain. So the moral of this story if all else fails try a poultice.
I hope to be able to post pictures as soon as I get permission from the car company involved.
Kev Martin