Hello, outis, I just wanted to tell you that I have been giving my now fourteen years old dog Essiac tea daily for more than a year and that has kept at bay a breast tumor whitout never causing any aggravation symptoms and quite the contrary keeping her absolutely fit and healthy, but of course i don't know about the type of cancer you describe. Only one more thing, what you describe as weeping grey gunk may be a detox taking place via lacrimal glands, so just clean her eyes regularly maybe with euphrasia tea or chamommile.
I would also suggest you give her some pills from barley grass (that's the only ingredient) from "Green Supreme". I have also given those to my dog and those are great as detox too. I hope your doggie gets better.