I haven't tried, but some time ago I stopped giving an afternoon bottle as he wouldn't take it anymore. I think he associates the bottle with sleep and refuses to have milk (unless its the morning one) he's going to bed. I realise this is my own undoing, but, it works.

I was thinking along the lines of warm water with a bit of sugar, but the warmth is a bit of shock to him and refuses to drink it, seems to believe 'hot, hot' (very cute when he says it) even though its not. So he gets that its water, but its not his regular water.