More on what astronauts found “objectionable” and “distasteful” with Apollo's system, from the PDF linked in the OP (1):

"In general, the Apollo waste management system worked satisfactorily from an engineering standpoint. From the point of view of crew acceptance, however, the system must be given poor marks. The principal problem with both the urine and fecal collection systems was the fact that these required more manipulation than crewmen were used to in the Earth environment and were, as a consequence, found to be objectionable. The urine receptacle assembly represented an attempt to preclude crew handling of urine specimens but, because urine spills were frequent, the objective of “sanitizing” the process was thwarted.

The fecal collection system presented an even more distasteful set of problems. The collection process required a great deal of skill to preclude escape of feces from the collection bag and consequent soiling of the crew, their clothing, or cabin surfaces. The fecal collection process was, moreover, extremely time consuming because of the level of difficulty involved with use of the system. An Apollo 7 astronaut estimated the time required to correctly accomplish the process at 45 minutes.* Good placement of fecal bags was difficult to attain; this was further complicated by the fact that the flap at the back of the constant wear garment created an opening that was too small for easy placement of the bags.** As was noted earlier, kneading of the bags was required for dispersal of the germicide.

*Entry in the log of Apollo 7 by Astronaut Walter Cunningham.

**The configuration of the constant wear garments on later Apollo missions were modified to correct this problem."

1: https://ntrs.nasa.gov/api/citations/19760005603/downloads/19...