Review (5/5): It takes a few days for it to start working but it worked
About 4 days after using the product, just when I was ready to request a refund and leave a negative review, the skin started coming off. If you have an half an inch thick callus, don't expect this or any other product to magically melt it away. You may need an acid for that. But it did take off 2, 3 layers of skin. Naturally it was more effective on already softer skin such as between the toes where I really didn't need to have skin taken off and less effective on the heel where I would want it to be more abrasive, but I understand that you can't have those things in one product.
Even though it instructs not to peel off the skin and let it come out by itself but as you can see in the picture it was way too satisfying.