Green Flashing screen after water

Hey guys, I’ve had an iPhone 10 for nearly 2 years now, a while back I accidentally smashed my screen and got it replaced for cheap, although I am quite certain that he did not replace the adhesive. Recently the phone has been exposed to water (not much at all) and the screen goes off and flashes green, although the touchscreen still works. This is the third time that this has happened. I have checked the sim card slot and there is no red sticker indicating water damage. The first time this occurred I left it in rice and overnight and it did work the next morning. I stupidly made the same mistake a second time and the demonic green flashing screen stuck around for 2 months, only to randomly start working again on a Sunday morning. Now I have made the same mistake for the third time… (i know what you’re thinking don’t worry) Am I right in thinking that I just need to open up the phone and give it a good clean, rather than just taking it for a pointless expensive repair? Advice, please!!