Tom writes: "So my fridge started to stink, and I realized it’s been about 9 months since I put in a box of baking soda. So on my way home, I stop by the grocery store to pick up a few items, including baking soda for the fridge, freezer and one for the laundry closet. I realize that 9 months is a long time, but no matter, I took a look at the box. Somewhere between November and now, Arm and Hammer decides that you need to change your baking soda more frequently – instead of once every three months, now you should change your baking soda monthly. Hmmm… I’m not too sure about that – even though 99¢ really isn’t that much, monthly seems a little excessive. Maybe the “Grocery Shrink Ray” is set to shrink time periods instead of sizes for Arm & Hammer."