It has always annoyed me no end when people make fun of and denigrate the old Civil Defense information, including films and some of the pamphlets. While we NOW know of some better techniques and have some better products available, in those times the advice those involved in the Civil Defense program were giving the best information they had available to them at the time. Almost all had the welfare of the population in mind when they worked on the projects, unlike what is now often the case where certain agendas are the primary driving force for government information packets.
The Duck & Cover program did give good information. It certainly would not save everyone, but it did give those in areas where survival was possible a much better chance of doing so. The program was never intended to save people within the zones of total or near total destruction. The same with the shelter program. A PF-40 shelter does not protect from high radiation levels. But it does protect people in the zone where the initial fallout radiation is 100R/Hr or less, with some radiation sickness expected, but survivable.
Of course, PFs of 300 and above are much better, with 1,000 and up being a start to where people can survive much closer to a detonation, or where fallout from several sources accumulates.
But anyway, doing some of those things advocated in the late forties to the early 70s can be highly effective in protecting one well enough to be safe long enough to begin the recovery process.
Just my opinion (and rant, too, I suppose).