When I did the KLM / Guangzhou "stop-over" some years back, it consisted of a few people leaving the plane, a horde of old Chinese ladies swarming down the aisles with dusters & rubbish bags, and then a few passengers getting on.
The rest of us passengers weren't allowed off & just sat there for about 45mins.... then the plane roared off down the runway.
I got the distinct impression that KLM had bought a landing slot there, and was just going through the motions of using it....... perhaps to preserve the licence..... and purely looking at it as a potential future long-term strategy.
