In The Traveller's Tree by Patrick Leigh Fermor, a travelogue from the Caribbean, he gives an account of water divination. He initially sees it as some voodoo myth, and is taken aback when they repeatedly find water.
Ok, if I point at a random spot in the ground in an area that generally has water, and I said, "dig here and you will find water", and you put 1/5 a mile of pipe down into the earth and water comes up, am I some type of miracle? Would those people work in the desert? I think it's a lotto ticket that always wins.
I think there is a more functional and charitable read of this: not all of our senses are plumbed all the way through to our conscious mind at all times. small little hints (like minor changes in smell, relative humidity, maybe just pattern-matching on the lay of the land) are down in the noise, and pulling out your trusty sticks gives your subconscious a way to send a signal to your awareness.
Kinda like acupuncture - does my pulse really have seven levels that mean different things? I doubt it.. but a successful acupuncturist might still be able to diagnose "what hurts" using said technique, when really they've already picked up on other clues from your gait, posture, etc.
"subliminal" and "subconscious" are over-used and vague words, but we've all had the experience of wearing a new clothing item and receiving an uncommon number of compliments, including from strangers who wouldn't know it's new. I've always assumed we are unconsciously presenting the new thing with a bit of flair, and that equally-unconsciously draws the eye.
You have to be careful of what you mean by "does it actually work".
Does the dowsing find water hidden in a random spot or is the dowser tapping into subconscious knowledge about the land to find it. The parent is talking about the latter.
Look up "Ideomotor phenomenon" in your source. It's right above the pseudoscience bit.
It's not like subconscious knowledge must be valid subconscious knowledge. The ideomotor phenomenon is an expression of internal belief, which may be little different than a wild-ass guess.
There's no evidence that the dowser is tapping into subconscious knowledge in a way that gives results any better than - or different from - chance.
These people do work in the desert. I have a buddy that drills wells here in Arizona and he WILL NOT put a drill into the ground without a Witcher. I have a really hard time with "witching" from a logical POV, but my buddy and his $130k truck/equipment swear by it. I call that putting your money where your mouth is.
The test would be finding a spot where a witcher says there isn't water, and then drilling there.
There's water almost everywhere in the ground -- the questions are is there enough of it to meet the need? is it usable (ie: not contaminated with salt or toxic chemicals)?
the depth of the water table is fairly well known throughout the world, and it is not like a series of underwater rivers which are easily missed; the water table is called a "table" because it is very large and very flat.
if you are within 100 miles of a natural body of water, or in a flood plain, or anywhere that it rains semi-regularly, drilling will get you to a source of water.
