Zatula
The zatula, also known as the rubal, rubel, rebra, kuchelka, kachanka, and kachalka, is a Ukrainian washboard also occasionally used as a folk percussion musical instrument.
The zatula consists of a piece of wood with grooves carved into it. A wooden rod is run over these grooves to soften clothes after washing. A musician plays the zatula in a humorous way, by placing the rounded rod under the chin and using the zatula as a bow, playing over the rod, or vice versa. The rasping sound thus produced is similar to that of the derkach.