I have been dowsing now for over 20 years, I can use both pendulum and copper rods. The pendulum is about 85-90 % accurate for important life events, less so for material quests. The copper rods are great for locating
Buried items like pipes, minerals' any object matters not what it is made of
Accuracy +- 6". It is easy to learn and is an aspect of magick that is useful.