Manufacturers and people claim that these foot detox patches absorb the toxins of your body, cleansing it while you sleep, and making you feel better when you wake up in the morning. This process of foot detox is meant to be as effective in removing toxins from your body as normal sweating if not more. Or so the manufacturer says.
However, in my humble opinion, the effectiveness of these foot detox pads is questionable. While feet do sweat and expel toxins, the skin that covers them isn't permeable (because the skin in general isn't permeable), and thus these foot detox pads fall short of the promise of complete cleansing of the body. I believe you could wear a sweater all night and achieve the same result.
A reason people think these best kinoki detox foot pads work is because they change color during the night. In reality, it's the sweat of your feet that does this, and if you ever try just pouring a little water on the foot detox pads, you will get the same result.
To finish, I believe that the effectiveness of foot detox pads is based on the willingness of people to believe they work. If you think they will work, most likely you will connect any health improvement to them. We shouldn't underestimate the power of our own minds.