Nope, gerryh's got it right, citing from the second link I gave, the man was a fake. I've no doubt he believed in himself, he wasn't a conscious fraud, just deluded. You're right that lots of people still believe in him, but that doesn't mean anything. Lots of people believe all sorts of stupid things without a shred of evidence: astrology, palmistry, graphology, reflexology, homeopathy, iridology, spirit channelling, astral projection, telepathy, telekinesis, clairvoyance, talking to the dead, dowsing... ah, the list is endless.
I think you have a lot of it right, Dex, but people have found water using a willow branch.