the infamous 'pyramid of poo' is a common problem with stationary rv's and
trailers that sit for weeks or months between road-trips. Just don't let the
blackwater contents dry out - turns into a pile of papier-mache and solid
wastes.
When i was full-timing, i used 'marine toilet paper' which breaks down more
easily, and used the hand shower to keep the stuff from piling higher and
deeper. If this problem does develop, fill the blackwater tank about
halfway, add a bag of ice cubes, and take the trailer for a short drive down
a bumpy road...
tuna
reno, nv