Glyphosate, a phosphonate, was discovered by Monsanto chemist John Franz as the company was looking at several phosphates to use as water softening\ chelating soap agents for spray additives and to clean sprayer tanks with, as phosphonates and phosphates are soap ingredients. Therefore, it's an easy chemical to clean out, because it has some of the the same properties as soap, which if you let soapy water sit around it gets gummy too. I usually tilt tank to drain, then rinse tank with several shots of water, letting it totally drain out in between rinses, after tank is clean, run clean water through all of the nozzles for several minutes. I've never used any cleaning agent and never had any carry over symptoms. A trace of roundup in water will make foamy soap bubbles, a sure sign that your equipment's not clean yet. The Monsanto company itself recommends only water to clean Powermax out of sprayers.