Abstract: Example apparatus and methods for homogenizing liquid manure in a cesspool are disclosed. One example device includes a pontoon to float in or on the liquid manure and a stirring unit held on the pontoon and to be immersed in the liquid manure. The example stirring unit includes a first stirring screw to rotate around a first rotational axis and a second stirring screw to rotate around a second rotational axis. The example first and second stirring screws are oriented such that the first rotational and the second rotational axis are substantially orthogonal to a direction of motion of the pontoon.