TheCadet beat me to it. I was going to mention LSD/shroom experiences. Never did it myself but of course I've read about it. I had friends who did it and just because it's interesting, I'd try to get them to explain the things I've heard are experienced - ego death, important insights into reality, coming to know your own mind. They'd seriously try to explain, but it just sounded like gobbledygook even though I trusted it was real to them.
I don't know exactly how the conversations have gone with you, but I can understand, that would be frustrating for any of us.
According to the OP, you're saying you don't accept the EKG because people don't/can't explain the knowledge, and so you conclude that the knowledge doesn't exist. It's similar to the question of the existence of God itself. If I ask you to believe in God but I can't describe Him fully and concretely, then you won't believe. But it's a doctrinal position you're taking, not based on evidence, but on perceived lack of evidence.
And I don't mean to nit-pick over your word choice, but you called it "esoteric", and then disbelieve it because it's esoteric. If it actually is esoteric, you can't really disbelieve it on that ground.