The Windex I use has vinegar, another mildly acidic mix that seems to do a pretty good job as a "starter" cleaning fluid, followed by regular cleaning processes.
Two reasons I don't dump water down the bore is that it can migrate into the wood if you're clumsy like I am, and it can get all over the carpet in the living room if you clean your rifle in front of the TV, like I do.
Besides the which, Bubbles would get sooooooooo angry if I stuck a bayonet into that carpet......
Denis