The description on kvraudio doesn't make much sense to me. How a procedurally controlled variable length delay line should be related to a pulsewidth isn't clear, the next phrase contains an even weirder contradicton: The input signal's fundamental frequency is a sine wave an thus has nothing related to a pulswidth.
But you could have a look at kink~, the number of accessible controls makes me think, they might have a really simple procedure...;-)
You could also try to create a procedurally controlled variable length delay line. tapin~/tapout~...
Then play around and listen (I didn't listen to the vst, I have no idea what it soumds like...;-)
The description sounds also weird to me. If I would describe what I hear, it's like the effect of a classic variation of pulsewidth on a square oscillator but for an entire audio Input. Don't know how this effect is done.