For many years the Leonine exorcism has circulated with a heading that says lay people may pray the prayers for personal use. One of the leading authorities on both exorcism and liturgy in America asked the Vatican commission who said while that is true they ask lay people to refrain from praying it for fear of the blowback they may receive from evil spirits.
This prayer was very helpful to me so I regret taking it out of future copies but we must always be obedient to the Church. If you have purchased the book with the prayer in it please refrain from praying it and you should never ever use for prayer over another.
If you have any questions please feel free to contact me.