I did it. Twice.
I had a Macbook from about 2012. This was when they first changed to non-lead solder and this had problems. I had got a reasonable backup. The machine was useless in its current state, so I would lose nothing. I had a fan oven. I am a materials scientist, and the videos I saw seemed plausible. I took out the motherboard, and stripped off everything I could. You don’t have to melt solder to anneal it. This got me several hours of a working machine, which let me get more stuff off onto a USB drive.
There were plastic plugs I could not remove. These get brittle. But when it went wrong again, I popped it back for another go. It worked for longer this time because I had an improvised cooling system. Yep, I only got a couple of days more, but in my case it was enough.
I also had a heat gun. This was less controllable than the oven - it could melt one bit while other bits stayed cold. I did not know where the problem was, so the oven seemed safer.
So, IMHO, the web is not just people trying to get you to pop your phone in the microwave, though there are plenty of those too. There is a logic to this. It can work for certain values of ‘work’.
