MeGrimlock, do you live in a particularly warm part of world or work in direct sunlight? ONR drying so quickly does seem strange. Might be worth spraying one panel at a time, give it a few seconds and then wash with the ONR.
As others have pointed out, taking an hour or two to wash a car is not a bad thing, in my experiment above, all I did was clean the exterior panels, not the wheels, door jams, wheel arches etc.
I would try and find a way of washing the car without ONR drying and then think about getting faster. Is your car quite old or possibly have single stage paint?