How can I discourage inappropriate and gross behavior?

When my mother was in the throes of this awful disease, her conversations were about 75% about sex. Sufferers from this disease are known to lose their inhibitions. When my mom got particularly distasteful in her remarks, I would not hesitate to tell her “Mom, be a lady! Ladies don’t talk like that!” And I said if she continued, I’d leave. It helped. It’s ok for you to tell her not to do something. Use a firm but not angry voice. I’ve said here before that I don’t believe in tip-toeing around people with dementia for fear they’ll spontaneously combust. I never yelled at or insulted my mother, but I didn’t sit there and listen to her pornographic diatribe, either.

Caring for people who have dementia requires a lot of patience and endurance. I'm not aware of any way to prevent certain behavior with people who have dementia. They aren't capable of truly understanding their actions. They don't know it's gross. So, I might try to not focus on the unchewed food and start supervising her toileting, so that she does not have the opportunity to handle feces.

You might also check on You tube for videos addressing dementia behavior by Teepa Snow.