The problem with many of these museums and even the medieval sources they're based on is that there's a strong incentive to make things as gruesome as possible,

The problem with many of these museums and even the medieval sources they're based on is that there's a strong incentive to make things as gruesome as possible, including just making shit up. For example, everybody's heard of the Iron Maiden, but all existing devices appear to be "replicas" and there's no properly documented case of such a device actually being used for execution.