>If any of this stuff worked, there would be commercial applications by now
Criticism A: Lots of people claim to have made money off dowsing/clairvoyance for mineral exploration. Debunking them is nontrivial. McMoneagle would be a tough nut to crack.
Criticism B: If an oil company is using an alleged clairvoyant such as McMoneagle, they are not likely to be candid and are not likely to cooperate with debunkers.
Criticism C: The market is frequently unfair and genuine working inventions don't always get to market.