I am uncertain whether I can agree with that. Belief,like everything else, is a spectrum. It ranges from the gullible fool to the cynical shill. In my time, I have happened upon both ends of that spectrum and every shade between.
My father was into stage magic. Not my gig, I prefer close-up and impromptu stuff. However, once (among many) I assisted at a concert, he did his thing on stage, I managed the hardware and so forth. At the end, we were packing up and we were accosted by a heaving bosom of righteous indignation, fulminating against our display of satanic, ungodly powers, and on and on and on. This ...thing believed it was real.
To this day it is not uncommon for me to be accused of demon worship when I perform an illusion, but that was the most vehement, vitriol and spittle filled, bile-ridden catholic delusion it has ever been my privilege to witness all of it borne out of superstition.
And thus we come to dowsing. The easiest person to fool is yourself. Yes, back in the day, I did so briefly, until I said "hey, wait a minute" (kudos to pops) and checked it out for sure. He said not a word, but I think he took a certain pride that I figured it out myself without prompting. In later life, it became a competition. "Betcha can't figure out how I did that". It became somewhat of an amusing good natured arms race.
Many times, when pressed to demonstrate a "trick" he would catch my eye and give me the nod, and we would proceed to pull off illusions that would grow in the telling afterwards amazingly. This is one of the things which made me understand what eyewitness testimony really means. Often, people recounted not only what me an my father did, but even things which never happened.
The bottom line is there exist people who believe I violate the laws of physics. I am content to leave them in their pit of gullible belief. It gets me party invitations.