You may recall a post from a few months ago about takesumi, otherwise known as bamboo charcoal. This nifty material has quite a few handy household uses, including deodorizing, balancing humidity levels and keeping produce in the fridge fresh longer. Check out 6 Reasons You Should Use Bamboo Charcoal (Takesumi) for more.
More recently at the store, I came across deodorizing activated charcoal in small, vented, plastic containers you can use in your fridge, freezer, produce crisper/drawer, or in places such as kitchen cabinets, shoe cupboards or closets. The brand I saw was 脱臭炭, but kenko.com has another brand of the same type of product.
Granted, you could just buy a box of activated charcoal or bamboo charcoal at your local home store, but I wanted to share this option as well.
Each specific type contains activated charcoal, though some of the other ingredients vary (for example, the freezer version contains alcohol). For those of you who aren't sure what each type is (there are pictures on them, in case you were wondering), they are:
Refrigerator use - 冷蔵庫用
Produce Drawer/Crisper use - 野菜室用
Freezer use - 冷凍室用
Meat/Fish Drawer use - チルド室用
Shoe rack/cupboard use - 下駄箱用
For use under the kitchen sink - キッチン・流しの下用
Closet use - クローゼット・押入れ用
You may be able to find these (or a similar item) at your local daily goods/drugstore, and you can also check them out and order them (among other brands) on kenko.com (the link goes directly to the items).