1. Remove power immediately. Remove the battery as soon as humanly possible. If it is plugged in, hit the breaker quickly. The faster you eliminate the toilet water from getting powered on the circuit board, the better the chance of survival.
2. Shake the device thoroughly if it is an item that will handle shaking it. Clean the outside of it with a paper towel.
3. Open the device to expose all places that are wet, if practical.
4. Blow out with canned air. Avoid using direct heat as it may damage your circuit boards and melt its adhesives.
5. Enclose in a container filled with dry white rice or dust-free cat litter. This will help draw moisture out of the item without damaging the components. Leave in this cocoon for at least 48 hours during which you pray fervently to your deity that the damage isn't permanent.
6. Blow back any residual dust/rice out with canned air and reassemble.
7. Take a deep breath and power it on.
8. Viola...there is a chance you have saved it from the electronic landfill. If not, do not throw it away. If it is a computer, bring it in for data recovery. Sell it on eBay being honest its condition...