For some people who are still struggling to get their head round the way the AquaTap works, below is an explanation I done in the window-tools forum..
Maybe this will help. Imagine just now you are holding the pole with your brush on the glass, you try and turn your pole a quarter turn and it won't move. Now imagine putting the AquaTap on the top of the pole, it can turn a quarter turn, so now when you turn the pole the bottom of your pole will make a quarter turn, and when it does it turns the water on. And when you turn it back a quarter turn it goes off again. If you hold the bottom and the top of the Aquatap it will turn and stop one way, then you can turn it back. That turning back and forth is moving something inside the Aquatap that allows the water to pass through, or its stopped by passing through depending if its open or shut.