Trying to spout conkers in the fridge… is the fridge method successful?

My little girl is trying to grow a conker tree. We successfully called sprouted, apple tree seeds and have apple tree seedlings on our windowsill.

She now wants to move onto conkers. We have eight conkers on a damp paper towel in a plastic container in the fridge. But they are not sprouting. They’ve been in there a couple of weeks.

Anybody got any hints, or tips to sprout the damn things . We have a carrier bag full of conkers.