Of course you know I HAD to go to AMAZON and search for "Poop knife". No luck. Turd slicer either.
They do have poop knife T-shirts, in case you're wondering, as well as a poop knife recording you can buy:
https://www.amazon.com/Envelope-Pap...F8&qid=1516456028&sr=8-12&keywords=poop+knife
Try eBay: Poop Knife