Your run-of-the-mill shoe stank might not pose much of a survival threat, but trench foot certainly will; baking soda is great at absorbing the moisture that might otherwise literally cause your feet to rot off your legs. As for the health of your teeth -- it will be pretty hard to get through your day's rations of homemade jerky and hardtack without some high-quality chompers. And you certainly don't want to rely on that pesky fluoride that will "kill your brain over time" (um, what?).
When you go back to the last depressing days when we were in a survival mode, the last one the Y2K of course, before the 1970s, what had happened was you only saw this one element of survivalist, you know, the caricature, the guy with the AK-47 heading to the hills with enough ammunition and pork and beans to ride out the storm. This is a very different one from that: you're seeing average people taking smart moves and moving in intelligent directions to prepare for the worst. (...) So survivalism in every way possible. Growing your own, self-sustaining, doing as much as you can to make it as best as you can on your own and it can happen in urban area, sub-urban area or the ex-urbans. And it also means becoming more and more tightly committed to your neighbors, your neighborhood, working together and understanding that we're all in this together and that when we help each other out that's going to be the best way forward.
Say you're at work and a terrorist attack occurs. Roads are closed to any and all traffic but you only want to get home - even if that means walking. You may not want to grab your full on family pack in the car or you may not even be able to get to it. But you just want a light kit to get you through. How far is it to get home from wherever you may be? This get home kit should provide for 1-3 nights of traveling on foot till you make it home.