To repair wet electronic boards , like a mobile that has entered him water, as this Nexus 5X that, despite rapid action he took water by charging connector, speakers and hole cards, it is best use pure alcohol or distilled water and an ultrasound machine , in addition to rub with a soft brush on the visible parts (and still no full guarantees, as if you were running shorts could damage a chip).
If you do not want to complicate , and you have 30 or 50 € which typically charge for repairing these problems, better take it to a repair center phones with good professionals, you will leave no trace of water or debris and running (but do not light after the accident), or try the Waterrevive liquid (which works very well if turned off immediately).
But if the water has not reached penetrate into the metal lids of the base plate (where sensitive to interference electronics is hidden), we can obtain very good results without ultrasound machine with brush and distilled water or alcohol (alcohol It has the advantage that evaporates easily later).
Waterrevive : A couple of young Spaniards have developed a liquid that promises that your phone back up and running in 98% of cases, they say. This liquid (possibly alcohol, distilled water or other solvent of mineral salts) introduced displaces water (containing mineral salts) preventing depositing causing short circuiting. Using this system has good result if we turned off / disconnected the battery quickly, before the lime and salt is deposited. If that system will not work, you can try these indications (100% of cases so far) .