Made by Scott Amron the Rinser Toothbrush solves the problem of watering the mouth for rinsing teeth.  It features fountain-making tunnel integrated within handle.  By just putting it under the faucet the tunnel creates a soft pressure of water that comes out as a fountain. A similar concept was introduces in 2007, spotted at ohgizmo, but that was never really available. But this newer brush can be pre-ordered for $22 and it will be shipped in November.

Available at amronexperimental.com for $22