 That would be a telltale sign that it's some sort of fungus, algae, or mold. So that's one guess. The wet and forget would be the interior or the exterior would I use? The one you use in the shower or the one you use outside? Well. The one outside you need is sunshine, right? Yeah. Use neither one of those. They have a third product. Okay. And a third product is called wet and forget disinfectant and mold remover.