Should they obey the woman who treats people with ruqyah?
Question

 
My mother used to take a woman who recites Quran to my grandmother’s home so that she recites on our grandmother. As my grandmother is old, disabled, and reached the stage of senility although she is not very old. This woman recites Quran on my grandmother and sometimes on my mother. One time while she was reciting she held my mother’s head so my mother started screaming. I did not see this but my mother told me. Now my mother goes regularly to this woman and she takes my sister and me with her. When she recites on my mother, my mother raises her hands like if she wants to hit someone, her nails come out and she starts saying threatening statements and slanders the Quran.
This woman told us that she is possessed by a devil, and that our mother is under spell. She also told us that the devil wants her to become disabled like my grandmother and lose her mind as well. She advised us to read surat al-baqarah everyday and to recite Quran always at home. She also gave us olive oil, jujube, honey, black seeds and pressed dates, and advised us to use them always. She also advised us to spread water with salt and rose water at home alternatively on daily basis.
The question:
Is it permissible for us to use those things she gave us? Is what we do considered shirk?.
Praise be to Allah.We ask Allah to grant your mother quick and full healing by His Leave and to decree for her and you reward, patience and steadfastness. 
We do not see anything in your question that would make us say that you should not go to that woman who treats people with ruqyah. It says in the question that she does ruqyah by reciting Qur’aan, and she uses blessed oil (i.e., olive oil) and ‘ajwah dates which protect against poison and spells by Allah’s Leave, and the fragrance of rose water which gives one strength to resist witchcraft and hasad (destructive envy); some of them also use ‘ood (aloeswood) and bukhoor (incense) to achieve the same purpose. All of these are things that are acceptable in sharee’ah in sha Allah. 
But what we see here is the use of salt which is sprinkled in the house, and we are afraid that this idea may have been picked up by some of those who do ruqyah from the myth or belief of the common folk that salt wards off the evil eye and so on. 
We asked some of those who do ruqyah about that and he said that salt has no such effect, even though some people use it. 
What we advise you to do is to be fully aware of what words and recitations she uses in her ruqyah, and if she uses anything other than the Islamically acceptable words such as dhikrs, du’aa’s and verses, such as things that cannot be understood, or you have any doubts about her, then hasten to ask her about what it means, and ask knowledgeable people about her. Many of those who treat people with ruqyah pretend to be reciting Qur’aan to fool the listeners, when in fact they are using sihr (witchcraft) and trickery and using hidden words which they say or write in order to harm the sick person so that he will carry on coming to him and giving him money. 
See also on our site a number of questions on this topic: 11290, 12918, 21124 and 91901 
And Allah knows best.