Many years ago I was a partner in a garage. We had several tranmission jobs at one time so we decided to do a test of these 'treatments'. This is how I've come to use TransX.
First we took an old seal and a new seal and put it in a couple of different products. One looked like it inflated the seal to twice it's size and it was mushy. The TransX expanded something like 10 or 20% on the old one, nothing on the new one.
Then we took a part (it may have been a servo cylinder) that was streaked with pink-orange. As varnish-y as it gets inside a tranny. It cleaned it to bright and shiny quickly. Good solvent.
The complaints ranged from slipping on upshift to a leak to 'not going into gear like it used to' if I remember right. In each case we gave it the treatment as test with the customer's agreement. After a few hundred miles we dropped each pan and each was visibly cleaner as far as the orange-pink staining goes.
We changed fluids, added again, and charged something like $10. Each case was diagnosed as either possibly a leaking servo, glazed band, hardened seal, etc. Nothing totally broken down and nothing that appeared to be because of a broken part. Each was told the problem might come back in a day, or in 50,000 miles. No one can tell, but $10 today or tear it down for $1000. If it works, you just saved. If not, you took a $10 gamble.
We did all the maintenance on these cars, so they didn't go anywhere else. Over the course of the next few years (until I left) the leak never came back, all worked well enough the problem was considered 'gone', one had 50k more miles and still going, and the worst lasted an extra 10k or so. They were all happy with the results.
If a problem presented itself similarly, and we thought it would help, we always gave it as an option from then on. Many took it, all were happy. It didn't work every time, but a LOT of times. There are a lot of cases where it's effects address the problem. The goal was a happy customer, and if they wanted to spend the money, we didn't stop them. If a can of something will free up a servo or valve and cost a couple of dollars, and the alternative is several hundred $$ to poke around trying to find the offending gummed up part, why not try it? We started using it on all of our personal cars and not one had to have anything else done. Not very scientific on that one, but we statistically had to do something once in a while because we would have higher mileage cars ourselves... We were happy too...
A friend came to me a couple of years ago with a Buick Century that reved between first and second on the shift (big slippage). He took it to a reputable shop (and the one I'd take a terminal case to as well) and was offered the $2000 teardown. We tried the TransX and in about 50 miles it firmed up. It's still going strong. Was it a seal? Was it a sticky servo? A gummy valve in the valve body? Who knows. A $7 bottle saved him $2000. Still saving him. And with that slippage, he wouldn't have gotten too many shifts out of it if he just waited and did nothing...
Maybe it's brain waves or maybe it's actually cleaning something. Either way, it's always worth a try to see if it will work. All my cars have between 150k and 300k miles on them, from a 1965 to a 1992, and since I began using it a few decades ago, I've not had to do anything to a single tranny. However, before that, I was averaging 75k-100k miles before one had to be taken apart. That's a lot of time and money saved, so if I'm being silly, I'm being silly all the way to the bank...
And BTW... I'm gonna keep up this silliness too. I need to keep these transmissions working - you never know when I might have to drive one of these nay-sayers to the transmission shop to get their tranny overhauled..