Dirt, Water and electronics do not mix well!
Best advice I can give is to clean everything with rubbing alcohol then let it dry 100%.
The alcohol will clean the dirt and absorb the water, but letting it get fully dry is the real key.
I would place it some place warm (25 to 35 deg C) with no open flames near it (Sun Light or heater vent. -- Gas ovens are not a good choice) for a few days before trying to apply power.
If you apply power while anything is still wet, it will be damaged.
I have had about 75% success rate saving water drenched electronics this way as long as poser was disconnected wen the drenching occurred and has not been connected since.