Are human hands cleaner than the inside of a dogs mouth
No according to myth busters I think
Human hands are generally cleaner than the inside of a dog. However, it depends on various factor like how clean the person is or the general cleanliness of the dog in regard to what it eats.
Outside of a dog, a book is man's best friend. Inside of a dog it's too dark to read. - Groucho Marx
A dog displays a certain amount of emzines in there mouththat the human hand does not presently have.