Homeopaths might offer Arsenicum album 30C (contains less than 10 to the negative 12th power mg arsenic), with higher dilutions or additional succussion required for more powerful drug activity in serious cases. Moxibustion or distant energy healing are alternative modalities.
I expected this would be about the tendency of (male) athletes to reach down and cup & rearrange their testicles before, during, and after an athletic event.
But I guess it’s something different.
In woo theory, maybe. Bile originates in the liver and travels to the gall bladder, which retains it until it squirts some into the digestive tract when you eat something fatty.
Also, there is only bile. It’s yellow when it’s new (upper end of the digestive tract) and dark when it’s older (farther down the digestive tract). That wasn’t known in medieval times.
I was in Taiwan on business with a co-worker. He got a traditional massage at a place near our hotel and got cupped. He didn’t realize that they left marks until I pointed it out to him in the sauna. He was terrified that his wife would not be amused at all but they healed up in time.
It seems like it could at least have some benefit related to muscle soreness, knots, and tension, similar to getting a massage. Detoxifying though? That’s hogwash.
I first saw this practice in Vietnam in 1968. The day after digging a trench, one of my local workers came in with those marks on his back. His English was good enough that he could explain what his village shaman had done to alleviate the muscle soreness. I was properly horrified.