Act fast and disconnect the battery
Corrosion is the killer of all water damaged iPhones and removing the battery will stop the corrosion in its tracks. There are iPhone screwdriver kits available on TradeMe to help with opening it up.
The Rice Myth
If your iPhone has had liquid damage, we highly recommend to act fast to avoid data loss and send you device in ASAP. The rice myth on social media will only make you think you are doing something but in reality, its corroding away inside which will end up affecting the success rate of the data recovery process.
The Correct Way
If you can completely dry out the iPhone inside out then you may have a chance to do an iCloud backup. Never ever trust a liquid damaged iPhone for normal use. There will be hidden liquid in places you cannot see and places that just won’t get dry. Once you have your data backed up to iCloud, you can sell it on TradeMe or recycle it at your local iPhone repair centre.
If you cannot get your iPhone to turn back on, please leave the battery disconnected and send into Data Recovery Lab for a Data Recovery assessment.