"In 1975, Dr. Joseph Sharp proved that correct modulation of microwave energy can result in wireless and receiverless transmission of audible speech."
This highlights a huge problem that ELF faced: Most people don't understand this stuff at all, and cannot tell the difference. On the other hand, the researchers and Navy were always very reluctant to go into the specifics of the technology, for military secrecy concerns. Beyond the sensible secret keeping, this always results in a much larger vague area where people don't want to talk even though nothing serious would be leaked because the laws are strict and figuring out the exact limits of what's classified is itself fraught.
So if on the other side you got people who are chaining together all the even vaguely EMF-related news and discoveries, and associating it all with a huge military secret project that no-one wants to talk about, and on the other side you got a bunch of people who actually know what's going on but are unwilling to give straight answers to even relatively simple questions because they are scared of accidentally divulging some key details that are classified, lots of people drew the frankly reasonable conclusion that there is something rotten here.
To put it simply, the kind of massive transmitters used by ELF and VLF projects would not be useful for working in the bands where the Frey effect works. The most efficient antennas are half- or quarter-wavelength, which for the Frey effect would be somewhere around 10-20cm (4-8 inches).
Both of those of course use a way too high frequency signal for it to be meaningfully received by the Frey effect.
Heterodyne systems don't let you pack more information into a lower-frequency signal, they go the other way.
EEG "spellers" c. 2000 required a cooperative participant who's actively engaged in a behavioural task: you attend to the letter/word you want to send and thereby produce a different response when it (vs the other letters) flash.
Implanted electrodes can do a lot better but it's still not something that will let someone "slurp" your thoughts out of you -- it'd be like subvocalizing them.
Comparing this to Dachau suggests you’re feeling a massive amount of psychological pressure. Usually, when the mind is under extreme, prolonged stress, it can start to externalize internal thoughts as voices or 'beamed' messages. It might be worth talking to a professional about the distress this is causing you—they might have ways to help mute those signals.