OMG! That was the catch line from a commercial, but I can't remember the product! 
A bit before my time. I remember it as part of some comedy skit or gag from the early 70's, said with a faux french accent I think. Perhaps from a Warner Brothers cartoon? Would have to be Pepe le Pew then I guess.
A search reveals this gem: "Pillage of Lucky Strike's pitch for its cigarette was constant in cartoons: So round, so firm, so fully packed, so free and easy on the draw. Generations grew up knowing the phrase, but ignorant of what it once sold. As incorporated to comedy, it was a mainstay, and continued long past Book Revue. Humphrey Bogart got laughs via recitation of it when he guested on Jack Benny's 10/25/53 TV program, not coincidentally sponsored by Lucky Strike."
From this link:
http://greenbriarpictureshows.blogspot.com/2015/02/warners-last-in-library.html