Some folks have done it, but it isn't recommended. The double-yolk egg doesn't have 2x as much room, so space becomes an issue. Often the chicks make it partway through incubation, and quit. Sometimes one makes it, one doesn't . There are a couple of YouTube videos of the assisted hatching of a double-yolk egg with two live chicks, but just because they made it that far didn't mean they really were viable - some don't make it, even after all that. So the usual advice is, don't even try.I always wondered if double yolkers would hatch, they won't?