I looked it up out of curiosity as I did not know what it was either.
And it seems to be a prayer by High Priest Jake Carlson which is the one that follows:
In the Name of Almighty Satan/Lucifer and Mighty Prince Azazel!I hereby command that the spirit of JehovahTo depart from my mind, my bodyAnd my soul at once!!"Begone Jehovah, thou foul spirit of deception, homophobia, hypocrisyand ignorance!!"I command thee by the Great Prince Beelzebub!By the midnight brilliance of Satan/Lucifer the True God and Creator,I recognize thee for the pitiful vampire thou art,And I invoke the power of thy Adversary to bind theeAnd keep thee from infringing upon the freedom of my soul!"Get thee behind me Jehovah!!!!Get thee behind me Jesus!!!!Get thee behind me thou king of the slaves and worthless sheep!!!!Depart thou foul holy ghost and bow to the ever-jubilant God of thisWorld!!"In the Name of Satan, I reject thee!!In the name of Beelzebub, I reject thee!!In the name of Astaroth, I reject thee!!In the name of Azazel, I reject thee!!"In the Name of Satan/Lucifer, depart, foul Jehovah!Depart from my life and from my soul!"Thou cannot refuse my command, for it is no lessThan a servant and child of the Almighty and Ineffable Prince ofDarkness Himself who commands you!!"Begone vile Jehovah, foul Christ, deviant holy spirit!!"I cast thee out!!!!!!!!"Hail Satan!Hail Beelzebub!Hail Astaroth!Hail Azazel!"
-By High Priest Jake Carlson
I copied this one from a post in the Joy of Satan forum.
But I couldn't find anything by Jake Carlson himself mentioning this, and no mention of it in the JoS website either.
So if anyone knows more about this, please enlighten us.