Is what one of the sheikhs of the Sufi orders did, namely reciting over milk and sprinkling it on the corners of the house and drinking part of it, considered sorcery and charlatanry, or is it permissible?

There is no harm in reciting the legal ruqyah over milk and then drinking it, by analogy with what Ibn al-Qayyim mentioned regarding the use of Zamzam water over which Al-Fatihah has been recited for healing, and what was narrated about Imam Ahmad reciting over water and drinking it.

As for sprinkling milk in the home, there is no legal, rational, or experimental evidence for its benefit in repelling harm or attracting benefit. It is feared that this might be among the actions of sorcerers, in addition to being a waste of money, which is forbidden in Islamic law. A Muslim is not permitted to consider anything a means of attracting benefit or repelling harm unless it is proven legally or empirically.