howling sound, wavy sound wahtever, you will need a pedal that can sweep through a cycle. Flanger, phaser etc.
The hiss is just a source of sound to be modulated by the circling action of the efffect(phaser/flanger)
feeding a guitar signal thru those, can only get the guitar sound being modulated, in the end, it still sound like guitar, but processed.
it wanna play the guitar but get windy wavy sound, the first thing is to totally change the attack response of the guitar. In the end, guitar wont sound like guitar..