I have seen them advertised but an old timer showed me about 30 years ago how to do the "rotocram." Use your knife and cut all around the anus as deep as it will go. Cut a full circle then get a stick about as big around as your thumb and about a foot and a half long with a small fork and push it into the body cavity until it sticks out the butt. Then twist it around a couple of times and push it out the but opening. The whole thing comes out just like the new tool does. Throw the stick away and wash your knife.