I haven't heard this, but there should be a sample of it (with wah) in the Boogie Nights soundtrack. The music guy behind that soundtrack claims to have invented this great idea.
There is way to put aluminum foil over a Heil Talk Box such that it rattles horribly and produces the worst torn-speaker sound imaginable. The Heil Talk Box is a horn speaker driver, driven by your tube power-amp output. Where the driver pushes air out (a fairly small hole), there is usually an air tube that runs up to the guitarist's mouth, with a mic hovering nearby. Instead of the tube, put foil over the opening of the driver.
Heil Talk Box
Electro-Harmonix Golden Throat
Dean Markley Voice Box
Amptone.com ultra gear-search page
Home (amp tone and effects placement)