[prashnts]

I ended up rubbing it off. Used a mouthwash for it (alcohol didn't work, perhaps "microcrystals" did the job). If you do that there will be lots of micro scratches on screen, but it's still better than looking at stains, and quite pleasant in dark.

I couldn't get the replacement (didn't know "stain-gate" was a thing).

[kasabali]

Never use alcohol anywhere near an IPS screen. You might get away with it if it only touches outermost layer but if it leaks to inner layers the screen will be ruined for good.

[prashnts]

This... is a good warning (after I found this googling [1]), thank you!

But, this made me more curious; is there something specific about IPS panel (vs. TN) that I should know? In that link, it seems like that the panel survived but the backlight diffuser layers got ruined. Theoretically, one could replace that...

I ask this because I wonder if you meant the glass-sandwich construction of the panel when you say "inner layers", and some chemistry of the liquid crystals. Or am I assuming too much?

In any case, thanks!

[1] https://forums.macrumors.com/threads/isopropyl-alcohol-under...

[kasabali]

Unfortunately I'm not knowledgeable on displays. I only learned it after pouring isopropyl alcohol into SIM slot of an iPhone 6S. It hasn't touched on top of the display.

On the first boot it had a lot of moisty look and funky colors. After leaving it rice and under sunlight for some time the moisture has dried but left a dirty stain.

The nasty surprise was dead pixels. There's a grain sized area in mid-bottom left side of the screen, some black, some green colored. I'm not knowledgeable on nuances of different types of display defects but I've tried variety of things like massaging, stuck pixel fixer videos etc. but no dice, I guess they're proper dead.