We have had quite a lot of issues recently where people have found it difficult to clean with High Alkaline Cleaners such as Aqua Mix Heavy Duty Tile & Grout Cleaner.
I am sure a lot of you are aware of this and it is not my intention to try and "Teach you to Suck Eggs" but it is very important to pre wet any Hard Floor Surface that is porous including some Tiles, All Grout (Except Epoxy)and virtually all Natural Stone. Failure to do this will result in the cleaner regardless of manufacturer disappearing into the stone and becoming virtually noneffective. By pre wetting the surface to be cleaned it is the water that penetrates so that when the cleaner is applied it sits on the surface and can be worked in to where the dirt is and be most effective where it is required.
Hope this little bit of information helps.
Kev Martin
Marble Life Ltd