I’ve done it - it is real.
What worked for me is to take a coat-hanger, and untwist it so you have one long length. Straighten it out - doesn’t have to be perfect. Cut it in half. From each half, make a long, L-shaped piece, with 4 or 5 inches on the short side of each.
Put the short side of each in each of your hands. Hold them in front of you, chest-high or so, with the long ends pointing straight forward and parallel to the ground. Hold them loosely enough so the wires can pivot easily in your hands. Even better if you want, insert the short ends of the wires into a 6 inch or so piece of PVC pipe, so the wires can pivot with less friction.
Walk slowly in the direction where you think there may be water, keeping the wires as still as reasonable. When the wires pivot, likely crossing in front of you, there is your water in the ground.
It’s not magic, but likely physics. The water probably creates some small EM field, and the wires detect it.
“It’s not magic, but likely physics.”
No, not physics at all.