Initiation is probably a bad word for anything -- it is the process of obtaining knowledge or in fact knowing it already. The term itself is almost wasted air when uttered. Anyway, it's typically used by Right Hand Path organizations and Left Hand Paths that borrow from them. Initiation implies exclusivity of knowledge that you must "do something to understand" but my experience has been that there really is no such thing. There is no monopoly of knowledge or super-secrets you cannot get through your own efforts without minimal assistance. You were born with the same capacities as nearly every other homo sapiens on this rock. The more occult groups and LHP prattle on about exclusive secrets, initiations, and more them more I laugh at them.. in general..
As you explore you will find that they have ripped off way more than they have originated -- often from obscure sources (Eastern Mysticism, Ancient Greek/Roman, or really old stuff like Mayan) and merely have repainted them with their favorite red and black colors. Often not siting sources, or admitting that what they are illustrating is an adaptation. CoS is as guilty of this as ToS, ONA, and others. Originality died with Austin Osman Spare I'm afraid.
All of the "secrets" of the ancients were exposed by Crowley... Everyone else just remixed his albums. Trust me on this... You can read his material and Spare's and know EVERYTHING. =) I was a student of western occultism way before I was a Satanist. You can buy your initiation at Amazon.com now so why bother with these silly folks if you need a chat room there are forums that are free. Some research will have you knowing that Xeper=True Will(Crowley)=Nirvana(Eastern Religions)=etc. Yep, they're just borrowed ideas. Certainly, adherents to any of these will tell you they aren't bootlegging it but.. yep.. They are..
They had plenty of time to read the same books I did. Organizations like ToS strike me as much more "Grey" than black... Any conception of "Oversoul"/"True Will"/"etc" moves you directly to the RHP category as far as I'm concerned -- LHP people don't believe in these things typically. Other than name I feel Xeper/Thelema are nearly the damn same thing...
Happy trails!