I currently have these charcoal inserts in my running shoes. In the week or so they have been in my shoes, they have done a pretty good job of reducing the odors that running can cause. Some odor still remains, but these are not new shoes when I first put them in either. They do fit pretty well in my size 8 shoes (I have one partially pulled out to show it in the picture- they do fit completely inside the shoes.)
I don't believe these will work on super stinky shoes; but if you're proactive and take care of both your feet and shoes they will definitely help some.
I did receive these complementary in exchange for my review; however the opinions stated are all my own.