Works with any conductor like a ring or tape a paperclip to your index finger. I often touch the metallic part of my keys then use the key's to touch your door.
The pencil seems to work better, perhaps because the graphite has some resistance. I usually feel it a bit when I use a key.
In this case, the people in the warehouse were unable to carry metal in because the delay at the metal detectors would mean they got no break time. The nub of pencil would be ideal.
In this case, the people in the warehouse were unable to carry metal in because the delay at the metal detectors would mean they got no break time. The nub of pencil would be ideal.