Re: Storing primed pistol brass
When I have spare time and components, I often will assemble primed brass. I then double bag it in heavy duty freezer bags, and seal them with as little air inside the bag as possible. Less air equates to less moisture inside the bag. A twist of paper towel with some very cheap generic kitty litter (Bentonite Clay granules without any clumping agents or fragrances) can sometimes make a convenient and simple substitute for a formal dessicent.
Unless you are in extreme heat and humidity conditions which cause condensation on ordinary objects, a day or two's uncontained exposure to normal conditions is pretty unlikely to degrade your primer performance.