Please accept my apologies for the delayed reply. You appear to be lacking firsthand experience with interactions involving certain law enforcement agencies and persons who are subject to device examination. The first step will be production of a bit for bit copy of the digital media in question, followed by a quick analysis of the disk image. In many cases, said analysis will rapidly identify media regions which are likely to represent "hidden containers", and interesting interactions between the owner of the device and law enforcement personnel will commence shortly thereafter.
This may disappoint you, but it speaks directly to my original statement regarding the utility of hidden containers. The link included in my prior post was mostly intended to spur further thought, in the hopes that you would consider (at a minimum) the scenario I've just described. Given my apparent failure to spark that trail of reasoning, I elected to provide a more direct example in this post. Cheers.