IMHO the best procedure to follow in such a case is this (in bold stuff you need to do, the rest is just explaination):
- The first thing should always be to remove the battery, since the surest and quickest way to break your phone is a short circuit - without electricity, a short circuit does no harm. So a few secs can make a real difference here. This is really the most important thing!
Use fresh water to clean the phone (not demineralized water yet*), if it fell into salt water or was in dirty water for more than a few secs. This should be done within a few minutes of the incident. Do this, because the second danger arises from corrosion. This is especially true, if salt water is involved. Shake it a little and use paper towels to remove as much water as possible. We don’t want the water to dry inside the phone though (that will make it harder to get salts/limescale out of the phone again.
Anecdote: My phone fell into the Mediterranean and when I recovered it after an hour I had hard-core corrosion everywhere (e.g. 1mm deep holes in the aluminium back of the screen!). This was only because it was salt water and electrolytically driven (battery was still in the phone). I guess that I don’t need to tell you that that phone never worked again…
- Now you can return home or any place, where you can securely (without losing any parts) disassemble the phone as much as you can or dare. Wash each part again, but this time use demineralised water (any residue salts/limestone might kill the phone later), not alcohol**. Dry the parts with a (paper) towel, then put them some place warm but not hot (you can use the hair-drier, but only from really far away or just on no-heat-mode)
into a jar of rice or use silica geld beads ***
- I know that you want to see asap after such an accident, if the phone still works, but try to resist as long as possible to even put the battery back, let alone try turning on the phone. Never directly try turning on the device after it fell into water. In your case, that might have killed the device.
Clean all (golden) contacts with a q-tip, maybe use some alcohol on the q-tip instead of water in this step. Reassemble the phone.
Only now put back the battery and try to turn it on. If it is dead, alcohol in form of a drink can come in real handy now.
*demineralized/distilled water is also quite aggressive in terms of corrosion/pH.
**Alcohol dries much faster and is less agressive in terms of pH, but it is way more aggressive as a solvent. Especially the screen, painted plastic parts etc can be damaged by alcohol. If you can make sure it only comes into contact with electronics, you might use, otherwise just use demineralized water, dry it with towels and then let it sit in a warm place or a jar of rice for a few days. Corrosion is really not such a big issue, if it is not electrolytically driven (battery is removed!).
Also, if you have dried salts/limestone: alcohol is in contrast to water a non-polar solvent and thus not able to remove it. (As Johannes has pointed out: ethanol is polar!)
*** Rice does not to be really good either: