got to agree Shirl,
i was cleaning carpets at a health club last week, and the cleaners who do the everyday cleaning asked me if I had anything to clean tiles, as what they had been issues with was leaving a white haze on the changing room wall tiles. the tiles were a polished black and were cleaned every day.
Try this i suggested, " champion" and the results were brilliant, a quick wipe , a polish and they were gleaming.
I think they are onto their managment to source some

Geoff