The game Red Dead Redemption 2 is not only a step-by-step passage of missions. You can also find a lot of Easter eggs in it, which is what many players do. One of them is the witch's cauldron.
If by chance the character of the game finds himself in the Grizzlies woods, he will find a dilapidated hut. Once inside, he will see animal skulls and other magical paraphernalia. In the center of the house will be a huge steaming cauldron.
You will not be able to see the witch herself, but you can drink some of the liquid that will be in the cauldron. The result of this experiment will be the loss of consciousness of Arthur. In the future, he will just wake up near the witch's hut.
There is no exact description of what the advantage of this action is. Perhaps the character of the game gets some bonuses or additional attributes. You can only drink the black liquid from the cauldron once.