Clean as a whistle. I had to resort to that method when i dug a post hole right onto a buried obsolete tigerflex. Had to sever the tigerflex to allow hole digging to continue to a deeper depth. Tried welding a sawzall blade to the squashed end of a 3/4" piece of thinwall, but it kept binding. Mason's line to the rescue!! Once you get it going - do not stop or else it sticks. But when it cools, you can continue.