I'll answer these from a scientific perspective...
1. Do I have to be a dowser in order to use one?
We would first have to answer the question, "What is dowsing?" It turns out that dowsing doesn't work the way dowsers think it works. When scientifically tested using randomized hidden targets, dowsing works as well as guessing. So in real use, dowsing is nothing more than applied intuition, observation, and a little luck. That being the case, if you want to be successful with
only an LRL, then intuition, observation, and luck are necessary. But you can also add a metal detector to "truth" each hit, and only dig what the metal detector says to dig. So I would say that "dowsing" isn't really necessary, but
something is necessary to get results because, by themselves, LRLs cannot detect gold.
2. Do they really work or is this a scam?
LRLs cannot detect gold. As explained above, real results can only be obtained when something else is at play. LRL users do feel a "response" from the dowsing rods, and swear it's "working". But this "response" is a mind trick, and not real. For those who believe it is real, they are self-deceived.
Now comes the tricky question: Do the manufacturers and sellers really believe their LRLs are working? Are they themselves self-deceived? Or do they know the truth, and are running an intentional scam? In my experiences I've seen both, and I leave it everyone to determine who is who. You can almost always tell by their alibis and defenses.
3. This outfit: http://www.treasurenow.com/html/products.html invites clients to visit their shop for a free demo or training. If the units don't work as advertised, how are they gonna convince the client to buy one, especially when they cost up to $20,000?
They rely on a demonstration in which the prospective buyer tries out the device, and feels the previously mentioned "response". It is truly an eerie and compelling feeling. Practically everyone who experiences it for the first time thinks, "Whoa! That was weird!" Once you convince someone it's a real response and not a mind trick (and most people assume it's real), the sale is easy. I've personally watched LRL dealers do their demonstrations, and people stand there in unquestioning amazement. But with a little application of scientific rigor, those demonstrations become embarrassing failures.
- Carl