Is there a cheaper way to clean limestone

[billrt]

Hi Guys
I gave a customer a proposal using safe restore . The numbers are high and I believe safe restore is the way to go. My question ,is there a cheaper way that will make the building look good ?
Thanks for the input
Bill Regan
Regan and Son Power Washing

[James]

You have to do many type's of testing to narrow down what works? Sometimes hot water works or just use the correct chem.