The problem with asking them what it is about is that they don’t necessarily know. I know someone who used to use dowsing to find Kevarim. He used metal sticks and told everyone it has something to do with the magnetic field (of the bones?). However, people use wooden sticks as well. Some, who observed its effectiveness and also how it doesn’t work well when there are less clues, suggest that it is the person who is it subconciously.
Many alternative stuff might help as much as, and through, hypnosis.