I use a water shredder.
If I have some paperwork I want to destroy irretrievably, I run it under the tap in the kitchen, wad it up and moosh it until it’s nothing more than paper pulp, and no one could ever unwad it nor see anything written on it, and I toss it in the trash.
Works like a charm, doesn’t waste electricity, and the “shredded” paper can never be “reassembled,” so no compromising your information.
Great idea! :-)