Our little house doesn't have air conditioning, so we have some areas of the house that get stuffy easily - especially in the summer. So, I bought a bunch of baking soda last week to place around the house.
I thought I would pour some in my vases and other pretties sitting around, but then I had the idea to put it in canning jars. I used a little square of fabric with the metal band and left the lid off so that it is breathable. An occasional shake will stir up fresh soda, so you don't need to stir. Makes a fun way to use pretty jars and fabric.
I'm sure people have been doing this forever, but I felt pretty clever for thinking of it.