PROSOCO Sure Klean products are designed to safely clean the very dirtiest of building exteriors — whether it’s built with limestone, granite, brick, sandstone, terra cotta, cast stone or concrete. PROSOCO has been in business since 1939. During that time, we’ve developed a reputation for being a company that is willing to go the extra mile and always do the right thing. That reputation hasn’t just been built with promises, it has been earned with action—in the lab and at job sites across the country.