Just the words themselves will do nothing if you don't understand energy. Some people say words without understanding energy and it does work but those people have good potential they may not consciously understand it but they still understand it even if they don't know. Unless the demon is already nearby the words alone won't reach its ears.
A demon cannot manifest as any thing more than a spirit but can manifest in the physical world as a spirit and that's what's happening when you summon it but that's a complicated and misleading explanation. They are spirits and that sums it up.
They can appear before you in any form they want and many will come to you as animals or humans and sometimes abstract forms. They can also influence the minds of people and animals and in extreme cases that causes a possession.
And so demons can only be seen with the third eye but some people use it without knowing. And they can act like familiars and some demons even are considered familiars.
To Outcast,
I have translated some of Koeting's incantations that he says are an ancient form of Aramaic.
The one that you mentioned that started with "Alash" I have run through Hebrew and Aramaic and have translated it as such:
"Corrupt good God's fire with the dew that is swept away"
The meaning of the incantation I am still contemplating but if any of you are rather weary of being blasphemous (In a Christian point of view) or against a certain religion I would not recommend E.A. Koeting's invocations.
I am translating the other remaining of his recommended incantations and will be posting them on here if any of you are interested.
All the best...
Alas I am not able to post any of the translations yet because I am on holiday and cannot access my works and translations . I will however be writing a separate post on the forums when I arrive back home. Keep an eye out for those interested or curious.