A pendulum

One of my friends and I use a pendulum off and on. Lately, I have been wondering if the answeres I get are real or am I picking up negative vibes? I decided to google a question to see how to tell the difference. One of the suggestions was to say the following out loud. "This pendulum can only be used by my guides. No other energies, including my own, can affect the answers of this pendulum". I sent a message to my friend, sharing the suggestion. She agreed it sounded like a good idea.