If you looking to do it live - Hyperphaser through a metalzone through a wah pedal (set forward) in that order to get that nasally thrash sound. I think. That's where I would start conceptually. All cheap pedals. If your doing it on a plug in, you could find the tone with an eq and run through a flanger and a noise gate. Or you could get one of those fake guitars at walmart, the paper things.
if you're midi equipped:http://www.musiciansfriend.com/guitars/ ... 4AodzzTP2A
But this is all conjecture on my part. It's only what I'd take my first stab at it with if I were trying to cop it.
EDIT: An EQ, a Distortion, a noise gate/ limiter and Flanger and/or Phaser will get you there as well (and probably closer) than the first signal chain I mention, but I think the first one would be an easier and less expensive way to there with passable results using effects most of us have access to. You might want to google some interviews with Trent Reznor to see what he was doing around the Nine Inch Nails "Broken" album. The song "wish" features the same type of guitar sound where the attack comes on very abruptly, phases and decays sharply. And I know he has been pretty forth coming with tech data. Again, Just conjecture and 20 year old recollection at work here, individual result may vary.