I am being asked to bid on several water features with polished black granite, medium to heavy mineral stain build up. Sampled some abrasive cream cleanser, and it somewhat worked. Any other ideas?  

 

I wrote an article on using AO paper pads which works nice, but I really don’t want to do it and they will not understand if I give them a price.

 

Trying to train them in a way to maintain, …