Here's a way to score 2 free boxes at baking soda. I found this deal at Homeland, but I imagine you will find something similar at any grocery store that doubles coupons.
The smallest box of baking soda was priced at $.47 each.
I bought 2.
Used the $.50 off 2 Arm & Hammer products coupon from the November All You Mag.
Coupon doubled making both boxes FREE. :)