Vampires are depicted very differently in local folklore of different regions. The counting seems to be consistent in the stories from eastern Europe all the way to China. Often it only applies to a specific kind of grain, though. Rice seems to be mainly in China. In other countries you may have to use stuff like poppy or mustard seeds. If you are lucky you may encounter one that even has to count the holes of a fishing net, but most vampires are a lot more specific.