Don't know if this would be helpful, but friends are trying to ween their little one off middle-of-the-night bottles and so are only offering her water. I realise that this is different to the situation you have on your hands, but they are getting results. Now that Caitie is realising that all that's on offer is water, she is not bothering to ask for it. Don't know if this is perhaps an option if you find you can't take the bottle away... Get her to reject it...?