I think the cat is just trying to exhibit natural behaviors. When a cat kills a bird, for instance, he hunts it down, kills it, then begins to lick at the feathers and pull them off with his teeth. It kind of sounds like that's what you're cat is doing. Just like you provide him something to scratch on, he may need this kind of stimulation as well.
Considering he may swallow a small portion of what he's tearing up, not many things are safe. You'll have to look around and maybe find something that he can do this with. I imagine that the cat toys that have feathers on them are safe-ish, since the manufacturer has to know they'll come off. Maybe you can make him a toy. Possibly a tennis ball that you've attached Velcro to and 1"x4"1" x 4" (30 x 120 cm) canvas strips with a small patch of Velcro. He could rip these off and they'd be too tough for him to chew up and too large to swallow. I say a tennis ball, but for all it matters, you could take a square of wood, sand the corners and edges over and just put straight strips of Velcro on it to attach the strips to. You could drill a hole in the top and use a string to drag it along and entice him.
Whatever you decide, I think it's a good idea to provide a substitute, just like with a dog. When a dog chews something bad, you say, "no" and then provide something suitable to chew. If you catch him chewing the carpet, grab a toy and try to entice him to put that effort into it instead.