Wow, I am very sorry. You are very unlucky.
Let the time do its work, and do not rush to turn it on.
Edit: maybe you can try the rice trick --> put the sp3 in a plate and cover it of rice. Watch out the vents.
Agreed with this assessment. The motherboard is probably fried.Bummer! I hate to say this but since you've already tried to turn it on, it probably has been damaged. Water is a good conductor so, if you turned it on before it was completely dry, some components may have been shorted.
I hope I'm wrong and it eventually starts working again. Good luck to you.