It is very real. I have been doing it for over 40 years.
Located many a well, sewer lines, water pipes, utilities.
Always amazing, even to me. I have taught many, many.

I think anyone can do it, if willing. I have however,
had a few that could only do it if I held one side of the
stick and put my hand on their shoulder or was touching them.
I think they weren't doing the tension quite right.

Just about anything works. Wires, forked stick, broom...
Some more sensitive and selective. Have fun with it.