It is a development of the mechanism shown at:
https://youtu.be/WYCTav31Xbg
for an India student project.
Washing tub is fixed to orange vertical shaft, speed of which is increased thanks to two belt drives.
The video show two working modes:
1. Tub oscillation: red stopper is set at its forwards positon to limit motion of the pedals.
2. Tub rotation: red stopper is set at its backward positon (not to limit motion of the pedals).
Disadvantage: vertical size is large.
آی-ویدئو