Key word is DAMP!! Not WET!!

In the freezer for a few hours will work too.

I second the freezer.

^ This is the answer

Sell the hides with the board included.

Do this ^^

Take a towel and get it good and wet with warm/hot water then wring out all the water you can. Wrap it in the towel and in fifteen minutes it should come right off. Or if you don't have warm water available you can do as beaverpeeler says, but if you use warm/hot water it absorbs it a lot faster and limbers up a lot faster. Doesn't take long at all.

I've done this to get stubborn hides off stretchers a few times, and routinely do this turning hides.

that's what I would end up doing