Ideas for removing oxide from USB-C pins on the side of the board

Hello everyone, I'd need some wise advice on how to restore my old smartphone to recover my photos. The problem consists of the oxidized USB connector. Years ago, I was on a boat and due to a high wave the phone got submerged. The device worked but since then periodically I had to pass antioxidant on the USB connector. Unfortunately, now the connector has stopped working and charging as the oxide layer forms a bridge between the soldered pins on the board.

Local stores have refused to fix it due to lack of spare parts. I have good dexterity but would like to proceed in the safest way for the data, therefore without disassembling the device for now.

Do you know any product that can remove the oxide without the possibility of brushing it off? I was thinking of letting a finger of the underside soak so as not to risk problems with the battery.