OK, so my cup was getting pretty funky looking and I couldn't seem to remove the staining. I was frustrated and threw it in some water with biz stain remover in it. It cleaned it up like a charm!. Afterward I washed it thoroughly several times and boiled it as well to make sure any residue from the stain removal process was gone. Now I am second guessing what I did and wondering if it is safe to use for my next cycle. What do you all think?