I see this a lot. Just because there is no visible water lest in the device doesn’t mean there isn’t a puddle under a shield. Water damage is a extremely time sensitive repair and you did the right thing by acting fast. Unfortunately the device needed a ultrasonic wash in isopropyl or acetone. Nail polish remover might have been a good option at the time.
If the device has been sitting for a week with even a small amount of salt water id say she’s done.
As a last ditch effort i would do an ultrasonic wash anyway. Replace the screen and battery and see if you have any life. Id also try a new charge port and if you have a current meter, test to see what the device is drawing from the wall.
Hope this helps.