Left my phone in my pocket for a shallow pool we had set up (40" tall). Upon getting out, realized the phone was stuck in a reboot cycle. Once I got home, I tried leaving it with a silica gel pack over a couple days, but it still wouldn't boot (At this point, it would show a red LED light when plugged in, indicating it was charging). I eventually decided to open it up and see if there was still some moisture left inside, and it was absolutely swimming in water inside. I dried it as best I could, and left it with the silica gel while opened up for another couple days, but now it won't even display the red charging LED. There's a bunch of white staining on the metal surfaces inside, not sure what they are, but they don't clean off.

Very disappointed that a supposedly waterproof phone has completely died in its virgin interaction with water. Still, if anyone has any last-ditch advice on bringing it back to life, I'm all ears.

Hi there! i'm so sorry to read that.
Maybe your unit had some o-rings missing as you can see here:
viewtopic.php?f=191&t=348815

To bring it back to life, i suggest to replace the charging board. You can find it here:
https://it.aliexpress.com/wholesale?cat ... ard+bv8000

Already replaced the charging board, made absolutely zero difference. I'm a bit loathe to keep spending money fixing water damage on a phone that touts itself as waterproof.