One of my dogs eats her own poop. Why should I worry about clean anything? Dogs will drink out of toilets,mud puddles and anything else. Clean is good but, just ask yourself about the above.
I have never heard of dogs or cats dying from their owners not washing their bowls after they eat or take a drink of water.
My cats do not share the dog's water or food. One dog has her own water and food bowls. My new puppy has his own water and food bowls.