I, for one, don't have an answer to your question. Sometimes, no one does. I don't want to totally dishearten you but it's possible that 'we' can't help you on this one. (In your defense, it's also possible 'no one' saw your first post.)
Anyways, if you know who 'provided' the material that's stained, contact them or the raw material supplier. Other than suggesting that, wait and see if anyone has an answer this time around. My best to ya and hope this helps.