I hope the following question will contribute to the OP, rather than derail it, but:
I'm curious as to who got anything positive out of study tech, and specifically word clearing.
For me, this is the one piece of Scientology that I continually used from the get-go (and still use, though not as fanatically as the study tech would have you do - I don't feel the need to look up all 38 definitions of a word, if I look it up in a dictionary, and never applied it as fanatically and pedantically as the materials required). It was probably the thing that made me decide that Scientology worked. Because I did experience the yawning and tiredness and blankness if I read something without looking up the MUs, and I also saw it in other people. Does anyone else think that the phenomena of an MU are real? Imagined? Or some other reason for it?
For me, it couldn't be explained by saying stuff like "people often feel bored when they read something, and they yawn as a result". I occasionally brightened up suddenly when finding MUs, but more often it was just that the yawning stopped, and I felt OK about reading whatever I was reading, after looking up the words. I then didn't feel like I was sinking into a mess while reading. Hubbard said that the brightening up occurs when you SPOT the MU (not when you look up its meaning). My experience was more like one just generally felt brighter on the subject if you LOOKED UP the words (and didn't get bogged).
I was always curious about the mechanism involved. I supposed at the time that it had something to do with it restimulating the words in implants, which would then make your memory blank and restimulate the unconsciousness of the implant. But Hubbard never really explained WHY the MU phenomena would be as they were.
Anyway, that's one area of Scientology that I always found useful. It's also, fortunately, an area that doesn't require you to get involved in the organisation, if you can get the study tech elsewhere. Demo'ing things with a demo kit, on the other hand, I found to be a little ridiculous. It turned into a ritual that one did to prevent the course supervisor from pestering you, and to generate student points.
ETA: Of course, it was also one of the pieces of tech that Hubbard took from some of his followers and put his own name to, if what I have read elsewhere is correct. I knew of some people in the 80s who did the Primary Rundown (look up EVERY word in the Student Hat course, in alphabetical order), and heard from a third party that it drove them almost nuts. Even if word clearing tech is valid, I can't imagine that looking words up in that way would be beneficial. There's nothing like CONTEXT to help a word to make sense, and to enter your vocabulary. Making up artificial sentences is no substitute for that, in my opinion.
The Primary Rundown seemed to have all but disappeared by the early 90s.