We do it, but we're doing it a little different than what you're suggesting. We inject both chemicals at the gun, followed by a clean rinse. We blend our own chemicals to do this. In addition to having our own fleet washing company, we also market this equipment to other mobile washes. More info is found at our other website here: Bioclean System and Supply, Inc. - Your Environmentally Safe Cleaning Solution - The most advanced truck wash system available today!. I hope that answers some questions you may have.