Yeh, I am not sure I understand the whole concept of the briar breathing anyways. So, lets say that air passing through the briar was a "thing." It might not mean that cake passes through the briar. And, if air does pass through it, wouldn't the cake stop it? And, even if air passed through the briar, would it be enough to even effect the combustion? And, don't get me started on why that would make it smoke any cooler.
I have seen two pipes since hanging out at The Briary that had black gunk passing through the birdseye on the outside of the briar. It would ooze as the pipe was smoked like a slow pimple giving away to a slow pressure. It was gross. One was an Eltang, and the other was a Savinelli. One owner was grossed out, and the other took it as a sign that the briar was breathing.
I'm not sure that anything proves or disproves anything, but I am not sure as to why a pipe that would allow air to pass through the walls would be a good thing. It wouldn't necessarily mean that it would smoke cooler. In fact, with air passing through the briar, it would make the outside of the pipe hotter, I'd think.