What is the hemp knife in Degang Guo vinegar lighting?

Hemp knife can be said to be a building material. I have seen hemp knives made of gunny bags mixed with mud, which can play a reinforcing role. When the mud dries, cracks will appear. With hemp knives, it is like having fibers, which play a connecting role in mud, just like having steel bars in concrete. Degang Guo uses corn flour, which is not sticky. With the hemp knife, Jiaozi stopped talking.