What is the ruling on going to a woman who claims to know the unseen through "al-Jashfah" and burning the skin as a cure for bad luck?

What this woman is doing is a form of divination and claiming knowledge of the unseen. Therefore, it is not permissible for your wife to believe her in what she says or to go to her. Goodness has no relation to cauterization; rather, it is achieved by resorting to Allah and supplicating Him. Cauterization is a treatment for some physical ailments, but it is disliked.