I have a 8gpm hot water machine with a 20:1 ds injector . I want to pretreat my gas stations n lots and dumpster pads that are really nasty with EBC + surfactant before surface cleaning with hot water then a rinse down . I have a variable pressure wand with 200 feet of hose. Can I get enough chems down to get the real heavy grease and oil. Or do I need a different proportioner on my injector.