I have oil and I doubt that it might contain magic, what should I do in order to make this magic void?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

If there are signs which prove that the said oil contains magic, then it is not permissible for a person to use it or consume it because if he does so, he is subjecting himself to harm. It is forbidden in Islam to do anything that causes harm. The Prophet said: "Do not harm yourselves and do not cause harm to others." [Ahmad, Ibn Maajah]  Making this magic void in this oil with the Quran and legislated supplications is not tangible and it is not known for the person [whether or not this magic is rendered void]. He might believe that the magic is rendered void whereas in reality it is not. Therefore, it is more appropriate to avoid making use of it or consuming it as oil is very easy to get and it is widely available. 

Allaah Knows best.