Spilling plain water (hopefully not soda, coffee,etc) may have tiny impurities that may short circuit tiny electrical connections leading to erratic problems. With most cellphones, replacing the battery simply requires popping the back cover off using one of several plastic wedge type tools to fit between tightly snapped together phones. Best troubleshooting would be turning off the phone then removing the back cover. Once the cover is removed, either disconnect the battery and use a can of air to blow off any remaining moisture. With moisture blown off, leave the phone in the oven (having a pilot light) to dry off in the next few hours. A stove with pilot light can do the same by placing the phone with exposed electronics facing up on a thin dish to dry. The gentle warm heat should accelerate evaporating any remaining moisture clinging in nooks and crannies. When ‘cooked’ this way for several hours, reassemble and turn on the phone. Another alternate to accelerating evaporation of remaining moisture would be leaving the phone on top of the boiler or hot water heater. Heat radiating from heated water can help evaporate moisture.