At My Spit's End

I can't take it anymore. I feel like I spend half my day handing Harry his cup, watching him spit, saying no, wrestling the cup from his hands, and wiping milk off everything in sight. It's gotten to where he asks for his cup, then starts raspberrying before I even hand it to him. It has been MONTHS now. And I have no idea what to do anymore.

When I have asked folks for advice, they always tell me to say no and take it away, which is what we've been doing with no success. Or they say that it means he isn't really thirsty, except that he is begging for his cup and cries and cries when it is taken away. Or that he is testing us to be sure we'll be consistent in our response, except that we have been consistent for months and he hasn't stopped. (And I feel like the harder we try (including prohibiting raspberries when not drinking), the worse it gets (fifteen minutes of non-stop raspberries).) Or that he'll outgrow it -- when? when he's 40? Months, people, it's been months. Someone must have experience dealing with this successfully after the aforementioned efforts have failed. Please help!

Honestly, I feel like we are reliving the biting-while-nursing issue (which never got resolved), but in a way that is thankfully far less painful to me physically but which is bringing up some old emotional wounds.