In Revolution they apparently have bath houses and other relatively civil ways of keeping clean, even on the road. Hot water may be more of a luxury, but it's available.
I burst out laughing this week when Maggie was trying to tell her dad it was okay to move on, while flashing some insanely clean and white teeth. Pretty distracting.
No, really, it's relevant. "Dad, it's okay to let go. I'm not a kid anymore. I can take care of myself. You taught me that. How to be responsible. How to stand up for myself. How to floss after every meal. See? See?"
You know, with all this talk about zombies being immune to decomposition and toxic to germs: seems like zombie ichor would make really effective toothpaste.
Just make sure you rinse REALLY well afterward.