Hey ER, sorry about the late reply, been pretty crazy 'round here, finally having repair work done after last year's flood, so Casa de Pod has been swarming with workers. I wrote a response several days ago that got trashed during posting.

As far as dowsing goes, it's as good as a random guess. Your guy might have been in a target rich environment.

I've only seen it done once, at a hotel parking lot in Arizona. They were looking for the sewer line using dowsing to avoid digging up the whole parking lot. A few days later, they found the line, but had dug several dry holes.

However, I am a believer in the power of intuition, that our brains can pick up on subtle clues we are not fully aware of.