row-by-row exchanging and straightening up the skew-whiff and abused in-flight magazines , sick-bags , duty-free brochures and the plastic emergency information sheets ; row-by-row wiping and disinfecting all the grubby surfaces ; row-by-row removing used pillows , discarded blankets and all the remaining complimentary clap-trap ; then finally vacuuming all the detritus from around and between the seats .