I have tried all sorts of things but I can't get rid of it completely. I've let it dry in the sun for sages, I've washed it several times...and it's still there; faint, but noticeable enough so I can't wear it. Can I bleach it? It's 100% cotton and white. If so, how do I do it? Presumably I don't use neat bleach - what's the bleach to water ratio and how long do I soak it for? Thanks!