Chakka, and others who'd like to try it...My first attempt at dowsing came after reading about it in a science fiction magazine. The author of the article explained how to do it by using rods, rather than a pendulum. I tried it out by walking over a 3' diameter dry culvert running under the road, thinking that if it didn't work here, it wouldn't work anywhere. To put it mildly, I was very surprised when the rods just about wrapped themselves round my neck as I walked forward over the culvert. There's nothing wrong in starting out by trying it at a spot where you know for sure there's something there. If you're successful, you'll immediately be aware that you seemed to doing nothing to make the rods react as they did. Carry on from there!
When I moved into my present house, I knew there was a leak in the old lead pipe mains water supply from the street. By dowsing, I found not one, but two leaks in the pipe. Having locating them, I saved quite a bit of time and money by being able to dig up the rather lengthy path at the exact spots to do successful repairs.
Those who can dowse know they can do it. They are also aware that, for some puzzling and frustrating reason, that scientific tests don't work. Yet they carry on doing it, not least in the employ of the military and the government, local councils and utility companies. I cannot help comparing those who deny it, but will not to try it, to those officials of the Vatican who refused to look through Galileo's telescope.