 So putting that on the stains, letting it sit for a while, hitting it with a pressure washer or a scrub brush, and it'll take some elbow grease, and then rinsing. I'm not going to tell you it's going to remove it. It will certainly lighten it. You might have to do it a couple times, but it's a challenge to get rid of. It really is. But that's how I would tackle it.