They probably work, but they didn't work for me.
WAY too small for my US Women's size 11s. No particular sticking strength, either, so they immediately bunched up under the balls of my feet in slip-on, clog-style shoes, making them as uncomfortable as if I were wearing ill-fitting socks. They became unpleasantly moist and goopy feeling after a bit of walking (through an airport, so it wasn't especially hot). They get a couple of stars because they DID seem to stop odor for a short time, but I threw the remaining three sets away, and won't be purchasing again.
Rating: 2 stars