So the other night, I was a bit distracted by one of the cats as I dropped my strides to park on the dunny…
And forgot my phone was in my back pocket, which of course fell in 
Noooooooo 
To make matters significantly worse, at this point I noticed my partner had observed the ‘if it’s yellow, it’s mellow’ directive… which induced an extra moment’s hesitation to boot. Oh well, there was no alternative; I fished out the phone, popped off the protective case and back cover and whipped out the (thankfully removable) battery, but not before hearing some alarming sizzling noises…
That was not encouraging - despairing for my motherboard, I got on eBay and priced a replacement; it’s an aging Galaxy Note 2, so I only found three on offer, but the price was right - $50. But I certainly didn’t look forward to the wait for it to arrive, let alone the extremely tedious rooting, re-flashing, and endless configuring in store.
Anyway, I was on my way to bed, and figured there was a snowflake’s chance I could revive it, so I held off. Besides, I’m currently broke as a joke, and would rather spend the money on a replacement for the tired OLED screen. Any damage had already been done; there was little harm in letting it sit around wet once the battery was removed.
Morning arrived, and I glumly set about dismantling the phone (Samsung kindly employed Philips screws, but I was prepared for other eventualities from previous phone repairs; when you order a replacement screen or the like, they invariably throw in a couple of miniature Torx screwdrivers and a spudger).
With this miniaturised stuff, you have to be careful when you get stuck disassembling - it’s very easy to break something when the way forward isn’t obvious. I hit that point after I’d removed all the screws, so I dug up a YouTube vid that revealed the situation. With this phone, the chassis proper is stuck to the screen, and the bezel is part of the back cover, so I needed to spudge around the edge of the glass (spudging means unclipping, which can be fraught with danger - in this instance I was able to use my thumbnail, which is best due to the tactile feedback. If you can’t use a thumbnail, and you don’t have a proper spudger, a good substitute is a slightly sharpened credit card, or ideally a bass guitar plectrum).
Anyway, when it comes to working on stuff like phones and laptops, this spudging business is the main hurdle; it often requires a delicate balance between caution and force; you have to be patient, and also to be sure of the disassembly procedure - you almost always need to google up a guide. The other hurdle is remembering where stuff is supposed to go back, particularly things like longer or shorter screws and their locations. I have lots of practice with this so I just relied on my memory, but most folks will be greatly aided by taking pictures or sketching diagrams if in doubt.
So I get it apart, and there’s dilute wee everywhere (ew), and close inspection reveals several places on the PCB showing signs of shorting - greenish-white powder here and there. Very discouraging… at this point I was pretty sure too much magic smoke had escaped from the device.
But hey, there was nothing to lose by letting it dry out in front of the heater for a few hours. I picked a spot where it wouldn’t get hotter than 50°C or so, and laid out the parts. Having never successfully repaired a water-damaged device before, I set about googling what to do about cleaning the (almost certainly conductive) gunk off the PCB. I saw pros and cons about alcohol, and didn’t have any anyway… and then it hit me - I had a can of CRC 5-56, which is contact cleaner, and just about perfect for the job. By the way, WD40 is very similar stuff…
I even had an unused toothbrush at hand, so after the parts had dried off, I applied a little squirt to the problem areas and thoroughly brushed away with a gentle circular motion, dabbed it dry with a rag, and repeated to rinse. Left it in front of the heater for a bit more, reassembled, crossed my fingers, and hit the power button.
…
FUCK YEAH
I was gobsmacked - it worked.
I haven’t got around to checking the bluetooth yet, but everything else seems A-OK.
TL;DR: If I’d only tried the rice trick, even if I’d managed to get it entirely dry inside, upon re-powering the phone, the nasty shmootz on the PCB would almost have certainly meant the phone not only wouldn’t work, but it very likely would have caused further damage, killing the phone beyond repair. If you find yourself in this situation (you’re pretty much screwed if you can’t pull the battery, but otherwise), even if you’re a noob, you’re almost certainly better off getting the phone apart to dry it properly and clean it with WD40, or preferably CRC. Or at least take it to a pro rather than try replacing the battery and powering it up.
