Here is a nice tail of a very practical use of dowsing, that of car maintenance. In
“Australian Experiences”, by Alex Deans:
The article speaks for itself, but it shows just how useful and accurate dowsing can be.
There are a couple of other points of interest for those not familiar with dowsing. He uses graphical aids to obtain (in this case) numerical readings, which he says people are “amazed” by the correspondence between readings obtained this way compared with those taken using standard measuring equipment. Also, he uses a pendulum, which typically gave him a binary yes/no response, by gyrating in either an anti-clockwise, or clockwise manner respectively. It might be thought that this was the limit of its use. However, the motion could be nuanced, with any oval motion indicating some uncertainly.