iPhone 5s water damage, gets warm but won't turn on

Well, first let's stop putting electricity into these devices. Second let's find a good repair shop in your area that has an ultrasonic bath and does board level repair work. Or if you don't/can't find one in your area, iPad Rehab does the best work in the country and has an amazing mail in service. I do appreciate that you tried cleaning it with IP yourself first. But sounds like a tooth brush isn't gonna take this time

EDIT: Again the ultrasonic bath with bransonic, or an equal quality electronics cleaner with distilled water is the best solution. Before going microsoldering. Test a known good battery, lightning dock, and display. Yes, read what you wrote, you charged a battery