Battery draining fast 2 weeks after dropping in ocean

Hi everyone,

As a lot of people do, I dropped my precious phone (iPhone 6) in water a few weeks ago. Not just any water either, salt water. I took all of the steps to dry it out: put it in rice and let it sit for three days. I also tried vacuuming some of the ports. Overall, things have been great. There have been a few minor glitches I was able to "fix" and the down volume button no longer works, but everything else was perfect.

Before this all happened, my battery could last up to two days when I barely used it. When I began using it after the incident it drained quickly but after a few days it went back to somewhat normal. I was able to go through a whole day, if not more without charging it. Two weeks later and it drains in 8 hours again. I don't know what triggered it but at first it seemed the issue was resolving itself but now it has gone back to having issues.

I never did clean out the back of it but I can imagine bringing it to Apple would be an arm and a leg. Does anyone else have an explanation why it would be working fine one minute and all of a sudden the battery draining fast the next? And does anyone have suggestions to fix this issue without disassembling the whole phone?

Thanks!

Laura