No different than every other passive setup you see people building on here. Just instead of a metal theyre using liquid as a heatsink. Its certainly a cool experiment but could be vastly improved most likely I would think.
I havent priced mineral oil lately but I would assume one plus to this is it would probably be far cheaper to do something like this than your typical passive heatsink.
I would think a deep cookie tray style res for something like that would be a better option than those jars.