Black-Throats rub a black salve into their throats, if its been too long since they last had a bit of Black the stain on their throats eats into their windpipe, older users often have crusted holes in their throat. Someone on the Black cannot be poisoned by anything consumed orally and feels immensely confident in themselves. If used occasionally, the black salve will only stain the throat for 12 hours.
These substances are considered illegal in Kaun, bordering on nasty magic, and will be confiscated by Magical Police Enforcement
Credit to Matrox Lusch