Oxygen, not chemicals, is the key to odor elimination...'cuz when organic matter breaks down aerobically (oxygenated), it converts to CO2, which is odorless. In fact, done correctly, aerating the tank contents will keep it completely odor-free without the need to use ANY tank product. It's only when organic matter breaks down anaerobically (without oxygen) that it generates noxious gasses--sulfur dioxide, hydrogen sulfide and methane--which are actually lethal in high enough concentrations. And btw, although methane is toxic and flammable, it's odorless...it's the sulfurous gasses that stink.