If your phone supports IP68 and above dustproof and waterproof rating (mostly Apple, Samsung, Huawei high-end machine), directly flush with water
If not supported, you can buy mobile phone disinfection sterilizer (only disinfection, oil stains and other useless)
If there are difficult to remove stains such as oil, it is recommended to use wet wipes 75% alcohol or detergent mixed with water, wipe the surface of the phone, and then wipe it again with toilet paper and water.