As my personal experience rice can solve this problem. My little boy did pee on my laptop keyboard while watching cartoons.
Some keys had stopped working and few need to press hard. Somewhere I read rice has an ability to absorbs moistures.
I researched rice absorbing ability and put my whole laptop between rice like the image below. I left like this for 5 days.
After 5 days it was working fine. most of the keys are working but some still had the issue. Time being other non-working keys has also started working.