Dear JP
i don't say that double blind test is not good , you said it don't work cause it faild on test when people watching that , you're right but when you can absoloutly deny working of something you most prove that it doesn't work at all , at anytime and anywhere , but if it works only for one time you can't say that it doesn't work . i don't have any experience on DKL but the gravitator passed the test for me , maybe it doesn't work good some times that i don't know why but some times it's very sensetive to even fresh gold targets and for me happend that i found treasures by gravitator maybe it doesn't happen for someone else ,so i can't telling you it doesn't work at all even when faild on double blind test .
it's my opinion and i don't claim that i'm right .
best regards
Alex