You did the right thing by removing the battery and letting it dry out. To try fixing this yourself at this point, you should open up your phone. Unfortunately we don't have a guide on how to open that phone, so when you open it, please show us how you did it!
Once you have it open and you're at a step where you can see the logic board (the main circuit board in the phone), you should use some strong isopropyl alcohol (90%+) and a soft brush to remove any white-ish residue you see. Let the device dry <thoroughly> to make sure all liquid is gone (this should take less than a day in a warm, dry place if the device is opened up. Putting the device in a bag of rice can also be useful at this point.) When it is dry, put it back together, and you will have your best chance of it working.
My wife was yaking on her 8330 while getting a manicure. Guess what ended up in the nail soaking bowl? Yup!
I happened to be with her and the manicurist handed me her phone. The screen looked like a fish-less aquarium.
I immediately removed the battery (not bothering to power down the phone) and shook out what water I could.
I did not disassemble it. I wanted to try the following first.
Once we got back to the hacienda. I took an empty eight ounce disposable tumbler and put about 1/4 cup of white rice on the bottom. I then pressed the bottom of the phone into the rice in the tumbler (sans back and battery of course) and covered the rest of the phone with rice to the rim of the glass. I think it was about a cup and a half of dry uncooked rice.
I let it sit there for three days and then removed the phone, shook out the loose rice, and put the battery back in. It booted up and everything worked fine.
The rice is hygroscopic; it readily absorbs water. I will admit to holding my breath when I powered it back up. I was half-way expecting a short and some sparks.
for the keyboard , try to take apart the button membrane which is made of a white plastic film with dome buttons , liquid under this membrane will keep them in contact , take it apart dry and clean , stick it back (maybe with tape on the edges) or change it with a new one (less than 10 euro , ebay). i did it successfully on a pearl 8110 which is built the same way (sticking back the old membrane )