I know a guy in a wheelchair without use of his arms/legs and has a footpedal something like this (not this pretty) and it sits behind his back. He leans in a direction to activate it. The stinkyboard device looks like it could work the same way, even better with the return-to-neutral tech.

I only mention because unlike other footpedals this one seems like it could more easily be used for other things than just your foot.