You can purchase several different brands of bag/gelpack which are convenient and sanitary to use, along with various containers. We used

which is a standard five gallon bucket with seat and lid.

In use, the gelpack is opened, revealing a large plastic bag which goes into the bucket and contains the waste, etc. Within this bag is "Bio-gel" which interacts with waste to produce a product which can be disposed as ordinary waste (different products make differing claims). After use, this bag is sealed within another bag, constituting the package to be disposed. You also get toilet paper (not enough) and sanitizer. Ideally, one bag = one use, although it is possible to stretch it to two uses (not highly recommended).

All in all, it was simple, effective, and sanitary. We could not afford to let illness delay our work. It ain't cheap- two dollars plus per gel pack, but it is much better than a slit trench, etc.

I have a unit and gel packs stashed away for the next EQ plumbing disrupter - such is life in SoCal.......

The unit is versatile, as well. We needed to mix a large amount of plaster and the bucket served well in that capacity.
Geezer in Chief