I've watched a couple of the short Aquatap video clips, and for what's worth, I think it look very promising.
I am little curious, though, as to whether the method of actually turning the pole to stop the water flow, is also, again, going to be mimicked, inadvertently, as part of the twisting and turning techniques we inevitability employ in the normal day to day usage of our poles; say for example, when we apply a twisting torque to our poles to achieve a flick to clear the corners of window sills.
In situations similar to this, and due to the rotational on/off mechanism, we'd be changing the flow of water to the brush head at times we didn't want to.
Otherwise, if you can live with the 75g weight increase, I know that I couldn't, personally, I think it's a worthy challenge to the Aquadapter.