The burl on the root of the heath shrub is full of both water and nutrients for the plant.
While it’s living there must be a transfer of water and nutrients through a capillary system.
Everything I’ve ever read about briar mentions the raw burls must be boiled. This is to remove sap or something inside the burl that tastes bad. They’d not boil it unless they had to.
The most valuable in any pipe line is natural, virgin briar. With use it darkens like meerschaum, although since it’s not pure white the darkening is less obvious.
Thd temperature of a burning tobacco ember is close to a thousand degrees. Briar is so excellent an insulator only a quarter inch or so away from the ember you can hold a broken in briar pipe while smoking, and your hand burns at 140 degrees. I wonder if asbestos was as effective as an insulator.
Breaking in briar pipes has been mentioned in everything I’ve ever read about briar. I’m convinced the extreme thousand degree heat, more than the minuscule amount of cake, does something to further cure the pipe and improve insulating properties of the briar.
Whatever is going on during break in, if the pipe maker coated the inside of the chamber he did it to help out a good, paying customer.
Leave it alone and grit your teeth and break it in.
I’ve often wondered when somebody made the first briar pipe and fired it up, why they didn’t put it down and call off the experiment.