In painting, Chungking Hog hair is the best grade boar hair because it has better backbone and water resistance than other types of boar hair.
I'm struggling to find brushes made of this. Whether this is because brushes are, and brands don't see the value in mentioning it or whether the best bristles are taken for art supplies. There is a Chinese wholesale website listing chungking Hog hair and but I can't find these for retail.
Bristles are more common to find - there are vendors with them on the Made in China Web site.
I would think these brushless wild make the best boar hair shaving brushes.