It is possible, yes, assuming you didn't switch the camera on with the
batteries in - though a short may already have happened without you
doing anything.

It's salt water or an electrolyte that's the real killer of electronic
items - ordinary bottled water will generally not be a problem once
it's dried out.

Just ensure you give it plenty of time - stick it in the airing
cupboard for a while before you do anything with it.

It was often said that if you got salt water in your camera, the best
thing you could do was drop it immediately into a bucket of plain
water.