I'm back with the results. TLDR: After two rounds of gluing (separated by 24 hours), there is only a small improvement of the coil whine at best.
In the past few days I read this whole thread to collect some knowledge and then proceeded with the operation.
I did the first round with the Samson brand, then I switched to the second one. Both had a very good wicking action. My first round was a very clean application, I made a dry run with the supplied nozzle and realized I wouldn't be able to reach all edges so I tweaked the nozzle a bit by using a transparent tape:
This was a perfect solution, it had a half of diameter of the original one and was flexible. With this I was able to push the glue directly to the edges of inductors, without any mess around. The glue was wicking perfectly until it reached the state where the inductors were "floating" and I was sure the glue is spread underneath and around.
To avoid whitening of the surrounding areas I setup a fan and let it cure for a day. However I noticed the curing wasn't that fast, it was still runny even after a few hours. Eventually the glue hardened, but you could barely see there was any glue applied, the reduction of the volume was so significant it basically all but disappeared. At best, there were some glue stripes on one of the inductors where I was unintentionally more generous with application, like the last picture in this post:
https://www.techpowerup.com/forums/...il-whine-coil-choke-noise.294015/post-4964000
I think maybe the air humidity wasn't high enough (around 30% at 23°C) and it caused this volume loss.
Then I tested the coil whine, couldn't hear any difference and decided to go for another application.
This time I applied more, I let it cure without the fan (which of course caused white "snow") and sprayed a little bit of water on the motherboard (critical areas covered) to speed up curing. I also tested the coil whine again before it was fully cured (again no significant improvement could be heard) as this was suggested here to potentially improve glue wicking action.
This is the final state:
I don't believe any subsequent application would improve things (
post-5051054). If there were any air gaps I think they are filled now, unless there are pockets inside the inductors. I think the best substance for using would be something like a super glue, thin, but with no volume loss during curing.
Since I read the whole thread I think I'm the fourth (or so) person with a laptop and all were unsuccessful with this method. That's something to consider too. Maybe it works better on larger inductors as found on graphics cards. Since my laptop is older and outside of the warranty, there is no harm done, but I would think twice to do it on a brand new device - maybe only if there were no other alternatives.
I will report back if there will be any change to the coil whine in the coming days. In theory the glue can be in a liquid form in some areas. It happened to me several times where the nozzle of the super glue is blocked, but the rest in the packaging is still liquid. This could be the same - the outer shell is cured, but the glue in the coils can be partially liquid.
