Does anyone know the actual timing parameters of the click-sensing equipment? I agree that too fast is more common than too slow, but I wonder how slow I can do it and still expect results. I think slower (longer clicks with longer spaces between them) is probably easier to pick up at a greater range, as well, so I think maximizing that is a good idea.
As far as range, last winter I was working on night currency so I was in the pattern and heard 5 rapid clicks from a regional jet probably 20 nm away (he was reporting 20 or so east of his destination, which is 30 northwest of us) to turn on the lights at an airport we share a CTAF frequency with. The airport below me apparently picked up 3 of those 5 clicks because the lights immediately went to low intensity. So with a good radio and some altitude, 20 nm is doable.