Dude, don't be stupid.
Go ahead, put it in the dishwasher on warm. Take it out and let it dry for 4-5 days. errr...
The time it takes for that keyboard to dry out will be more then enough time for the metal inside the keyboard to corroide & rust.
Then you'll have a large piece of crap with letters and numbers on it.
Then you can throw it in the garbage.
Or, you can collect a few hundred cans or bottles and return them, then with the deposit you can buy a new keyboard....