Assuming you can rotate the flap valves, and I recall you probably could. It's a bulkhead mount design intended for this. The stroke is easy enough just beneath the hamper lid. It's a good spot, out of view and you can pull the handle and use the space. Because there is a anti siphon loop at the top, I think it just may be a tough prime situation. But the flap valves should respond to the bellows-closing one-opening the other- on each stroke, creating plenty of suction. Your idea of rotating the hinge may be just the little bit they need.