I don’t know anything about dowsing. All I know is that we were a 100 yds apart and had astronomically different results. I thought dowsing belong to the divination and “peeping” arts and decided to leave it alone. On my next house the sewer lines collapsed and I had to dig them all up. A dowser came out and laid the lines out exactly right. He gave me the copper rods and they literally jerked me toward the water main. He said I had the “power” and I should use it! I never got near those voodoo sticks again!
I think it has to do with body chemistry and the subsequent transmission of EM fields.
I don’t know how it works, specifically, but I know it’s not “supernatural”.
I have seen people find all kinds of lines. I saw an old guy pick up two sticks and find water lines. Also saw a guy bend welding rods and do it. The preferred rod seems to be copper rods or brass soldering rods.