I think braining may be the easiest. Not a lot of thought needs to go into it...just a quick slice down the head. The heart would require a little more thought and I would imagine that if the stomach was cut, you risk cutting into the rest of the GI tract, which could get messy and gross. Plus the brain stays held in place by the skull. A big slice to the body and things would start to fall out and be messy.
Sent from my iPhone using Tapatalk