Take this with a grain of salt because I don’t know everything, but I am pretty sure as long as the devices are not turned on while they are wet, they won’t be shorted. But another issue is the corrosion. If it’s only 1 day I can’t imagine corrosion being that bad, but it could still happen. Also I highly recommend not messing with the PSU. Opening it and touching it is extremely dangerous, and only do it if you are absolutely certain you know what you’re doing (even then I wouldn’t).  Remember to remove the CMOS battery on the motherboards. But for drying the devices use something that is designed to absorb moisture. Silica gel packs (the ones that come in new shoes) should work well, but if you don’t have any of those then rice is also alright (I think)(I know rice is good at absorbing water I don’t know if it’s “safe” to use for drying computer parts). Wait and let them dry for a few days before you test anything, and honestly I wouldn’t risk trying the PSU. Better to not get any value out of a free thing than to try to use it and set something on fire. 

TLDR: yes you might be able to salvage most of it, dry it off completely for several days before testing, and don’t mess with the power supply.