[meko]

'Common' in 'parts' is weasel-wordy with a tinge of orientalism.

Whether gutter oil exists in any capacity whatsoever, it'd be merely a brief encounter with rural Chinese principles and the commercialism of the developed world; therefore it won't stick around for long as China becomes more developed.

[beardog]

If I could edit my comment I would replace "common in parts" with "found in some areas". I used the phrase "common in parts" because it has been found in multiple cities[1] (in fairness, early 2010s), however I logically believed that it would be unlikely for this to be in every region of China, as it is a vast country with various cultures and levels of development. Some sources I've found claim it is a more common practice than others.

https://blogs.wsj.com/chinarealtime/2012/04/03/chinese-gutte...