Never heard of that one. If it's just sheetrock, it obviously needs to be torn out and replaced. Removing any drywall is never hard, but always messy. I usually grab a dust mask, straight claw carpenter hammer, and a garbage can. Drive the hammer, claw first, right into the wall and start pulling it off. A little finesse is a must, since there will be wires hidden in there and you don't want to do any needless damage to the insulation. The idea is to use the hammer to pull chunks off the studs. The remainder of the job will be easy, or suck, depending on how it's fastened. If it's just nailed to the studs, you're good. If it's glued and screwed, it can get ugly. The screws can either be yanked out with the hammer, or backed out with a screwdriver, or battery drill. As you may note, the glue does a great job of permanently attaching the back of the sheetrock to the studs. This needs to be scraped off the studs with whatever works, putty knives, chisel, etc....