I don’t think this is the best way to clean PCBs but it would make a great machine for marinating food, moving the marinade around continuously for max/even absorption.
This is not a cleaning process (in the sense of "removing dirt"). One way to create PCBs is to use a board with a copper surface, put a protective mask on the locations that should have traces or pads and then etch away copper from everwhere (else). In the end, only copper under the protective mask will remain. Etching is faster when the solution is moved around during the process. This machine does exactly that.
It would make a poor machine for marinating food. Most of the foods you'd marinate should be refrigerated during the process. A much better way to marinate is throw everything into a ziploc with as much air removed as you can to maximize contact. Flop it around every now and then if you like.
