I used to get many pocket calculators in for repair which had been dropped/soaked in various types of liquid. If the water contained any soap or detergent then just drying may not be enough as it may leave a conductive film on the circuit board. The chips and screen will be ok as they are sealed. The only sure way is to completely strip the unit down and rinse every piece in clear cold water. Then leave to dry on a wire mesh/grill wires so the air can get to all the parts. Leave for 2 days at room temperature. Not an easy job and not 100% guarantee that it will work.
I do this still on my TV etc remote controls if some keys or the whole unit stops working and actually wash the parts in water with a drop of washing up liquid then rinse and dry.

I do not advise any type of forced drying or the use of rice as it is dusty and organic and may leave a film on the circuits on which mold may grow weeks later.

Chris.