Water is the key...
High liquid to stuff ratio and no clogging.
In your house you flush toilet......1 1/2gallons or so push the stuff down a long slightly sloped drain line to septic or sewer.
No problems...right.
In your trailer water/stuff fall drop a short distance down a 3" line to tank......then when full that stuff is pushed down/out fairly short 3" line.
No problem.
Issues happen when not enough water is used, dumping tanks when liquid level is low or leaving drain valve open and having no liquid just a poop pile.
Think about it.......then put it out of your mind and go camping.