Just try it, for the lolz
Take a couple coat hangers or #14AWG wire bent and put them in both hands and go for a walk.
I thought dowsing was a load of bullshit, and so I thought, well, I'll just try it.
To my surprise I noticed the coat hangers can subtlety move and be consistent about something, that is they behave the same over the same spot in a room.
The stupid wires will move and cross over each other, like an "X".
I did more research and they think it's ideomotor movements, or a person tilting/leaning to one side causing the wires to rotate. It's very low friction.
-> Subconscious mind tilting your wrists causes the wires to rotate.
I still think dowsing is a load of bullshit, but the dowsing rods can be made to move and it sure is weird seeing that.