My BIL bought a new boat with a Cassette toilet, and I was in Marine Electronics at the time.
We boxed his compass and installed and tuned his HF radio, using the usual Budweiser lubricant, and decided to make a run from San Pedro to Catalina to check everything.
We didn't know that the toilet's valve was opened, and bought another case of Bud in Catalina.
At first, we thought the boat had a leak, but we did!
I also had a Thetford in my old TC, and am thinking about adding one to my current MoHo. Got a perfect spot for it, and with the GC's, it sounds like a good idea.