No you don’t need to see him or hear him. Maybe short meditation before you start would help. You don’t need a sleepy trance state. You just need to relax and let the pendulum work freely. There are many YT videos about it and how to use it, check them out.
Nothing complicated really. At quiet place, anytime when you feel you won’t be disturbed, light the candle and incense, hold the pendulum and call for him… when the pendulum answers that he’s there, you can ask him your questions and receive the answers.
Once you got all the answers. Thank him and ask him to leave. Simple as that