BRIGGS JOHN wrote:
"The operative adjuro te formula ... seems to have been favoured for use against a demon who possesses an individual. (The words exorcizo te are more often used in rites for the exorcism of things, which are actually blessings for those objects, such as for the components of holy water.)"
The reference is:
Florence Chave-Mahir, "Medieval Exorcism: Liturgical and Hagiographical Sources", pp.159-175 at p.170. Chapter 7 in: Helen Gittos & Sarah Hamilton (eds.), Understanding Medieval Liturgy: Essays in Interpretation (Ashgate, 2016 [December 2015])
The book is highly recommended (although a bit uneven) - I may well report further when I have finished reading it!
John Briggs