Is the pendulum really spiritual?

I think (only on behalf of my personal opinion) that using a pendulum is actually communicating with your subconscious, and the pendulum is a tool to reflect your subconscious.

As for how to use it, hang the pendulum with a wire or pendulum chain, and then practice using your consciousness to make it rotate clockwise or counterclockwise, or swing back and forth. Then you can chat with it or ask something when you are proficient, and it will answer you by saying "yes" or "no" in circles.