Also, use a bit of theater when pulling the tool out, perhaps, a feigned cell phone call, that can be cover for recovering the tool, you appear to be holding the cell so that you can see the screen in daylight while in fact your using it to cover pulling the tool out.
about rust, some kind of cosmoline in the hole would be able to also keep the nail from bouncing loose when the door is used. But don't use too much or it will come bubbling out on a hot day and draw attention to the nail.
I just love free associating, letting ideas come and go.
