Warning: gross
Of course, but the fundamental problem is that difficulties compound. It starts with: pooping is much harder when gravity isn't there to persistently tug on the turd. Something that is slightly obnoxious on Earth (using a bag, using a suit flap) turns into an absolute trainwreck when you have a bag, a suit flap, and turd separation failure. Now you have to do precise mechanical manipulation of an object you don't want to touch behind your back through a bag and a suit flap, every failure multiplies the work, and now the turds can float away to multiply the work outside your immediate vicinity. Ditto for kneading the antibacterial into the poo: if you fail to do this thoroughly on Earth, bacterial offgassing causes the bag to vent, but in all likelihood that's the end of it because you can arrange for gravity to keep the poo away from the vent. In fact, you would probably do this without even thinking or imagining how it could go wrong. In zero gravity, you can't simply arrange "vent on top, poo on bottom", so the event is likely to launch aerosolized poo into your living environment where you have to put up with it for the next few days.
It's difficult to fully appreciate gravity until it's gone.
Astronauts are heroes for the risks they take, but they are also heroes for dealing with this.
Seems like a big issue is I'm guessing insistence on having this be a solo operation for cultural reasons. Seems like it would be easy with two astronauts. Have the one bend over and spread the cheeks wide with both hands, the other basically does the hand in the dog poop bag trick right as the poop is coming out and wipes them up after. No worse than what a nurse does every day for work.