That's what the Chaos Marines want you to think.
Kai Guns are really powered by Hugs and Bunnies and Ponies.
Ever notice that Kai Gun operators always wore more spikes than the rest?
Clearly compensating for something!
On topic though: "Warp-based technology" isn't really that common. The Animus Speculum is kind of a weird one as it doesn't really operate because of the Warp itself, but rather the unique properties of the operators.
The Culuxeus are what's called by the Imperium 'Blanks' or 'Pariahs'.
They have no presence, whatsoever, within the Warp. It causes humans to feel discomfited around them, psykers are physically repulsed by their presence. They are essentially immune to psychic attacks against themselves because of this property, and they in essence channel some of that 'Blank' aspect into the Speculum, causing it to be used to shut down psykers from afar.