Layover 21 hours in Guangzhou Airport (twice)

Flying from Malaysia to Guilin. Will apply 144 hours free transit. Stay in Guilin for 4 nights. However, The plane will stop at Guangzhou Airport and layover 21 hours before going to Guilin. Can we go out of airport and stay one night and then come back for the flight to Guilin?

Will also have another layover 21 hours at Guangzhou Airport when we fly from Guilin to Kuala Lumpur. So can we go out of airport and stay one night and then come back for the flight?