Living In Europe. I have seen and used the water-less toilet. You see them in Gemany and France in gas stations. The sink wit sensor or foot switch you also can find there and are used for many years. In France they used the 1 push button (that comes back in +/-30 sec in sinks and showers.
The idea of collecting used or rain water (called gray water)and using that for flushing the toilet or watering the plants is also in use and build in in some new development projects in Holland.
My feeling with electric systems for saving water is that electrics and water do not mix well. It must be a low voltage system. And are we saving so much water compared to the electricity used for running this?
B-art