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’re cold and wet and in desperate need of warming up you need a dependable way to get a fire started. The Gerber Bear Grylls firestarter is simplicity itself with one end providing a ferro rod to create a spark and the other a metal striker. There’s a lanyard running through both ends so you don’t lose track of anything and a powerful emergency whistle on that same lanyard that will allow you to signal for help. The whole thing tucks away neatly into a waterproof storage unit that measures a modest 4 ¾” in length. Mastery of fire is what separates us from wildlife. This piece of fire-related survival gear can ensure you walk out of the woods at the end of your ordeal.
To me, the best option is to store emergency food. How much? If you have none, store enough for a few days. If you have enough for a few days, get enough for a week. How much you store depends on what time frame you think you're at risk for having to be completely independent. The early settlers of the southwest liked to store enough food for a whole year and still do to this day!