I'm not saying its right and usually I'm the first to get annoyed by their "liberal" use of 121.5, but if you understood Putonghua at all you would know that most, if not all, of the banter that goes on is actually operational. Half the time they are on a wrong freq so another aircraft has to relay the correct freq (very sloppy yes but not talking about pork exactly). Sometimes its a bit like the Chinese 123.45 version of North Americans asking about rides and whether directs are available that day or why not.