FWIW, I have had only one experience with a witcher, and it was a loooong time ago in Arkansas.
Perhaps 30 years ago, my folks needed a water well at the little cabin just built that we used for a vacation place. It was extremely critical to hit it right since the vast cost of the well would be incurred drilling thru a substantial layer of granite.
They befriended one of the local ol' timers; a guy named Plez (phonetic spelling). Plez witched with 2 long, narrow sticks. He would walk around with the sticks and watch the skinny tips. When he found the spot, he said the tips of the sticks would dip once for every 10 feet of depth to water. He counted off 11 dips and said to drill "right here". They did; hit water at 114'.
