Electrical – use low voltage lights with a motion sensor

I think your strategy of making a cone out of aluminum foil was on the right track, but your choice of material was not. Think about what happens when you put various materials in the microwave. Paper, glass, ceramic: no effect, these will be ineffective. Aluminum foil: unintended consequences, do not use. Then consider what the microwave itself is made out of. You are essentially making the window (which is a person window, the negative image of a sensor window) This suggests the use of a grounded metal mesh or foam. Locally in NYC, the SpyStore sells copper-nickel mesh fabric for unstated purpose. You should also be able to find self-adhesive EMI/RF shielding foam at various industrial suppliers such as McMaster-Carr. You will want to wire either material to ground. I would start by trying to disable the sensor completely by this method (of covering it with grounded metal mesh or foam.) Then open a small aperture in the opposite direction of the corridor. Increase the size of the aperture until the functionality is as you desire. Use white self-adhesive paper label stock cut slightly larger than your masking material to return the sensor to an all white appearance if that is important.

In this type of set-up, all load power is controlled by the electronic motion-sensing switch. If you use the mechanical switch to "turn on" the light, the motion sensor will turn it off when no motion is detected (after a certain time period, usually selected by the user/installer).

If you look at the wiring instructions for the 3-way motion-sensing in-wall switches you will see that they are wired a bit differently than a traditional 3-way circuit, although the number and type of wires is the same.