Pros:
No anesthesia. lol
Cons:
If an under the gums cleaning needs to be done, it can't be.
If they are wiggly, it would be more difficult to see in their mouths and get into the deep crevices.
If they are scaled, they need to be polished. Vibration from the toothbrush is something some dogs won't tolerate (including Ellie
).
In my opinion, unless your dog is too sick to go under anesthesia, I would do the best I could at home and have dentals when needed. I have thought about and still think about trying it anesthesia free, but I really doubt that they could do a thorough job this way.