Hello everyone,
I get a feeling I will regret this,

but here goes....
In my opinion, dowsing is not some kind of mental trick nor a special ability. I have a theory of why it SEEMS to work (even though it doesn't work 100% of the time) that is based on electricity. I have posted this elsewhere in T-net, but here is my theory.
You are carrying a pair of electrical conductors, whether a green stick or a pair of brass brazing rods (which is what I tried) as you walk around. All water and all metals have an electrical charge; (this charge exerts an electrical field and a magnetic field around it) as you pass over the body of water or electric wires buried underground, the two lightweight conductors in your hands react exactly the way two thin conductors WOULD act if passed over a source of electrical current, they are first attracted to it. They cross, and touch. As soon as they have picked up the identical charge as that in the water source (or metal) they are repelled from each other, often pointing in opposite directions (usually taken as the direction of a stream of water, which is in keeping with the electrical charge within the water) because electrical charges behave very much like magnetism - a positive charge repels a positive, a negative repels a negative.
It is a highly imperfect tool for hunting for things, because you get the identical reaction whether you are passing your "L-rods" over a buried electric wire or over water so you cannot differentiate what is putting out the electrical field that the rods have encountered. Worse yet, there is no indication of how deep, though there are a couple of ways used by dowsers in my opinion they are really guessing, based on what sure looks like electrical reactions. Nothing mystical, psychical, no special abilities or mentalist involved, simple laws of physics. If the rods are not held loosely enough, or the electrical field is dampened by interfering non-conductors, or if there is even much of a breeze, it just won't work right.
Now I hope I have not ruffed too many feathers with my own
personal theory of how dowsing appears to work, but it is simple to try it out for yourselves - just take a pair of L-rods (even bent coat hangers will work) and use the methods described elsewhere (hold them loosely, just slightly tilted downhill in front of you but just barely) while you carry them over an electric motor that is turned on; then try it over a water hose or pipe full of water and you get the same result - which is perfectly in keeping with the natural phenomenon of how conductors should react with electricity. Think of those old demonstrations in the schools with the Van deGraaf generators or Tesla coils, upon which a stack of tinfoil plates would be set - first the plates are attracted to the electrical charge, as the plates picked up the identical charge they are repelled from each other and fly off one by one. We are only seeing a similar reaction with dowsing. I don't think your mind or mental state has anything to do with it, unless your mind is making you hold the L-rods so tight they cannot react to the weak electrical fields around water, metal etc.
The practice is so old that we don't know when it was first done; some point to the story of Moses tapping the rock with his staff (and water poured forth) as a possible example of dowsing, which probably seemed like a miracle and was impressive to folks who had never heard of or seen it done. It doesn't work all the time, for many reasons as we have touched on - but it is a harmless pursuit at costs little to try out. I guess if there were some way to differentiate (with accuracy) between metals and water, I would sure do it myself but as far as I know, no good way of differentiating is known nor an accurate way to estimate depth.
I did not believe dowsing worked at all, until I saw it done finding water lines, and my friend showed me how to do it, which led me to investigate just how this might work. There are theories of imperceptible muscle movements, magnetism, mind control, ESP etc but I don't think I have any special talent and the electrical theory will "fit" with the evidence.
Oroblanco