I will concede, the article is not TOTAL B.S. They talk about the calculator and they are right on that one being a fake LRL, a disguised bent coat hanger that uses the placebo effect. I'm not saying dowsing can't work, just that it is outdated by thirty years, it's unreliable, and it's very difficult to learn. Any L-rod work is difficult to learn and requires constant feedback. Most people do not have the patience to stick with it. And without some form of meditation it can take years to learn especially if you learn on your own. As Fred Stewart wrote in his dowsing manual, if you start at the age of five and practice every healthy day, by the time you are thirty years old you will have reached you plateau. That does not mean you will be a good dowser--it depends on how much effort you put into it.
Anybody who thinks they don't need daily feedback is delusional. A common belief is that nowadays dowsing does not work nearly as well because of all the scrap metals in the ground and the electric signals in the air. Well, I read about some scientist about three hundred years ago (maybe longer) said that dowsing worked one time then missed the next ten or twenty times. So you see the myth--it NEVER was reliable. The delusional thinking is even worse for the map dowsing.