I just thought it could be a type of air freshener that was used on board to, as much as possible, eliminate odors of various kinds from 250 people cramped into the same cabin for hours.

well, here's my two cents worth,I worked for 5 years cleaning cabins for Delta and Hawwiian, and a year cleaning United airlines....and some Continental.yeah we all agree on the smell and discused where it comes from. but here's one for you...Delta planes, 90% of the time all smelled the same..Ive worked 727,737,757,767,md-11 md90, L10 11, and the nairly all smelled the same, however, there are the instances where they cooked fish in F/C and it smelled like fish...the front lave not serviced..smells like....well you know..and so forth....But there was a big diffeance between the airlines..United didnt smell like Delta...Delta didnt smell like, hawaiian and soforth...the hawwaiin .DC10's had distict smell, that could be smelled all the way down the jetway.not so much as there new 767, but intime they too, recived the same smell as the DC10....so...I have now idea , where i was going with this...I guess its just FYI :) but each airline had its own smell...so if you want that smell, just pic up some old seat cushsions, from your fav. airline:)and have at it