I am currently doing a job for a new construction site. The structure is almost 70 feet tall. When I took the job it was to clean the block. The company wanted me to use a chemical from "Prosoco" called "Custom Masonary Cleaner for final cleandown." Now here is my problem. I started the job today and the cleaner DOES NOT work on the mortar tags and smears. So I called Prosoco and they informed me that the cleaner is meant for sites that is only 14 to 28 days old. This site has been up for months. So does ANYONE have any ideas on what I can use to get these tags and smears off?