The battery is done. You can add distilled water to a battery if the level is low because the water evaporates from the acid. But if the battery is spilled where the electrolyte is lost no amount of water will bring the battery back to life.
You could go out and buy a motorcycle or lawn tractor battery where the electrolyte is in a seperate container and add that to the battery. But then you end up with a useless motorcycle/lawn tractor battery.
This is one of the times where you hang your head and learn from the mistake, and then move on.
Tester