Priced at $40 USD, the Fire TV Stick is a bit more expensive than Google's $35 Chromecast, but $10 cheaper than the already-affordable Roku Streaming Stick âlike other typical set-top boxes, the standard Fire TV is available for $100.
The precise question was: Is a dog's mouth cleaner than a human's? The answer to that is no, too, and basically for the reasons you've already cited. As we all know, dogs aren't particularly fussy about where they put their tongues or what goes into their mouths.
To human ears, a dog whistle makes only a quiet hissing sound. The advantage of the dog whistle is that it doesn't produce a loud irritating noise for humans that a normal whistle would produce, so it can be used to train or command animals without disturbing nearby people.