Recently, there was a discussion on Mi Yodeya about whether there was a Jewish source for the practice of divination and sorcery via blei gissen (Bleigießen, or molybdomancy). Based on the actual Jewish sources (e.g. in the Talmud and Rambam), what punishment would a "Rebbetzin" who performed Bleigießen, to divine information or cast spells, be liable to (in an age and place in which the Sanhedrin still meted out Biblical and/or Rabbinical punishments, and assuming she fulfilled the requirements of having been halachically warned (hasra'ah) and having been witnessed by two kosher witnesses)? What would be the punishment/liability of one who made use of her services?
I don't think the ability to differentiate rulings for magical practices is simple. See for instance Menachos 65a top Tosafos in the name of Rav Hai Gaon that explains the qualification of 'Baalei Kishaphim' to be on the Sanhedrin, is the knowledge of the craft to know how to rule for real magic verses trickery. There is a similar explenation in the Margolios HaYam on Sanhedrin 17a.
In general real magic in a qualifying situation for punishment in the times of Sanhedrin gets a stoning. Trickery gets Rabbinical lashes. Rambam hilchos Avoda Zara chapter 11 halacha 15. See there Kesef Mishna at length, concerning the Rambams earlier statement that trickery does in fact get Biblical Lashes, his differentiation between the cases would play a part in deciding what this lead pouring trickery would incur, if it is in fact trickery and not real magic or actually allowed.
Last, I would like to point out the practical ruling which pertains to this. The Shulchan Aruch in Yoreh De'ah siman 179 under the prohibition of sorcery says it is not allowed to inquire of astrologers or cast lots. The Ramma adds that the prohibition is from the pasuk תמים תהיה עם ה׳ אלהיך, we must have complete faith in Hashem. He adds and certainly a person cannot inquire of necromancy and witchcraft. The Ramma in the next siff adds that if a person happens to hear his future, he is not allowed to ignore 'his mazal', that would constitute relying on a miracle. However, one shouldn't seek out such information because of תמים תהיה.
The Shach #1 on the Ramma not to inquire of necromancy and witchcraft because of Tamim, says in the name of Maharai, the actual practitioner is doing an issur dioraisa. But if the inquirer is doing this for health reasons, it is allowed, because it is not a real issur, only Tamim. He goes on to quote the Maharshal that even a sick person is not allowed to go to a witch unless it is a life threatening sickness, even if the sickness will cause the loss of an appendage. But, if the sickness came through magic or mikra(?) and ruach ra, it is allowed. The Shach says the Bach at the end of the siman rules the same.
It is possible that sickness which comes from an Ayin Hara might deserve to be on the same list of supernatural diseases which witchcraft is actually allowed to be used to alleviate.