This excerpt comes from "Kaos" book:
Well the actual rub is, if in some sense they are trying to invest these fictional creations with some kind of spirit life -- making a kind of artificial spirit -- they are certainly not making the beings according to H P Lovecraft. Besides, only a complete and total idiot would... they don’t exist to grant power to mortals; they certainly don’t exist to be made tools of by mortals -- they want to devour and destroy... that’s what they do. And really, their description by Lovecraft is the only one that counts (ok and maybe his writing children). Even those magicians who suggest investing fictional creations with “life” to be in the realms of possibility, would probably suggest that you are dependent on the form taken by the being as it is already “described in the Collective Unconscious”.
If you call it Cthulhu but you describe it as a helpful spirit... well it just ain’t Cthulhu. Certainly the “shoggoth” summoning spells of chaos magick don’t represent the Lovecraft original; rather, just a borrowing of the name as it makes for kewl spelz. Mind you, many of these people also think that blood-sucking, undead vampires are real and that the main public view of them doesn’t come from the imaginations of the creator of Varney and Bram Stoker but was rather “channelled” to them to reveal the “Truth” -- as is often asserted by those who insist that Lovecraft was not the actual creator of his stories but a mere participant in an automatic writing sessions from “beyond the gates”. Lovecraft would likely suggest that such individuals were escapes inmates from Bedlam. That vibrating sound isn’t the arrival of a wandering evil from beyond the stars... it’s Howard Phillip spinning in his Rhode Island grave. The beings written of in the fictional tales by Lovecraft (an admitted non-believer in magic) or bastardized for role-playing games were so totally inimical to humanity that only those others who did so by accident were either dead, soul-devoured, or hopelessly mad by the end of the story. Heck even Satan himself is more approachable... for the cost of your soul. Lovecraft’s Ancient Ones “used” humans merely as weak tools to inflict themselves upon the earth. They were the great characters for horror stories. That’s it. They certainly don’t have the provenance of the majority of entities described in the grimoires, even if those beings’ only claim to fame or reality may be the test of time.
As to “if it works it’s good enough for me” well I guess that depends on how you define “it works”. If those who attempt to evoke Lovecraft’s fictional beings into appearance in the mirror don’t run from the mirror screaming insane gibberish or soiling themselves from fear, or die on the spot, then it didn’t work -- you got a wrong number. Sure you may have invested some shade of your subconscious with life and named it Yog-Sohot-toddie... but it ain’t “the dweller on the threshold”.