Cleaning granite type flagstones

by Kaine
(Dorriez)

Hello. I was wondering what you believe the best type of cleaner is for cleaning granite type fieldstones. I've used muriatic acid and have not gotten the best results. It seems to do little or nothing when following the directions when it comes to application and dilution. After having no luck from following the label I used the acid without diluting it at all and left it on the stones twice as long or longer than directed with no sucess either. It seems only good for etching concrete. Do you sell a product for cleaning the types of Michigan stones I have here? (mainly granite and other types which are simila; grainy and very hard) Thank you very much for your time, Kaine Dorriez