 That's great, but it doesn't actually remove the problem. So with a closed-loop plumbing system, you have residual water, especially in a washing machine, you get stuff coming off your clothes. All of that builds up over the course of time. And so then you start getting that moldy, mildewy smell. Now it's time for awesome. You just drop a half a teaspoon of awesome right into your empty washer, run it on a full load with no clothes, but like a large load of hot water.