Vodka Watermelon. Simply cut a hole in the top of your watermelon the size of your spoon/vodka bottle neck. Scoop out a little bit of the watermelon to make room for the Vodka Bottle. Place the Vodka bottle upside down in the hole. Let sit for 6-24hrs until most of the Vodka has been dissolved by the watermelon. Place the watermelon in the fridge to chill. Then cut into pieces and serve.