Any mud is good mud ... (Any BTO fans out there? You ain't seen nothing yet

)
https://www.youtube.com/watch?v=cFRk0FfaQi0I saw these guys in concert. That dates me as old as mud. Sorry for getting off track. I can't help myself.
Where I sink it is mainly the black river mud along the stream bank and exposed mud flats. I have found it deep to the point were I cannot get deeper than my shoulders/neck. When the mud is just starting to become exposed, once it is worked a little, I can almost swim in it.
When I was a kid I played in an abandoned brickyard and the clay there was absolutely fantastic. This is probably were my fetish started. I continue to scout for this kind of mud and have a location in mind but the water level needs to drop some as it is 300 miles one-way.
As far as suction ... when the same river mud described above starts to dry out a little it is extremely sticky. I wade through the wetter stuff easily then get seriously stuck in the dryer stuff. I have to be careful not to get a leg or foot cramp when trying to get out.
I have never been in peat but would definitely like to try that.
I believe that I have experienced true quicksand i.e. fine sand that packs tight once you stop moving. This was in a gravel quarry in the wash pond. It was one of my first sinks and I was very inexperienced so I only went knee deep. I have no immediate plans to return there. Kind of dangerous to do alone and the T word helps shut me down on this.
Thanks for the question barefooter.