I agree - and in true scientific fashion, my own experiences are my litmus tests, and I trust the results! :-)
And I know by my own experience that water dowsing down to (in my case) 120ft works as proven by the dowser who dowsed and drilled my bore hole and told me beforehand where it was and exactly how deep it would be.
Now, tomorrow I am off to King Arthur's Hall with a dowser who uses rods and a quartz crystal pendant. I'm after something special so we'll see what happens. The dowser has no idea where we are going or what I'm after but I've said to expect a fair walk :-)