My daughter got bbq sauce on her shirt so I have been soaking it in a sink full of cold water so it wouldn't stain. Somehow the water drained out of the sink, and the shirt has been sitting in there damp. It now has purple mildew on it. I have tried a couple things off Pinterest and nothing is working. She has worn the dang shirt only once ♀️ Any methods that you have tried that's worked? It's not white so bleaching is not an option