You know what is the natural way of getting rid of smelly shoes stink? It is very simple. All you have to do is to take some newspaper and crush it, make it into a ball. Stuff it into your shoes. Put it there over night. Next morning the bad odor will be gone.
Newspaper has carbon and carbon is the best thing to absorb bad odor. You can do the same for your fridge.
Just put a few piece charcoal wrap in cheese cloth or any cloth with holes. The cloth is to prevent the charcoal from dirtying your fridge. I bet the smell will be all absorb by the charcoal. It is natural and definitely safe!