Review (3/5): It works, but you have to be careful where you use it.
My experience with this stuff is a little humorous. The first thing to note is the instructions are under the barcode sticker. A second thing to note is that even though this stuff is supposedly made in the US, the English on the bottle is not the clearest.
I followed the instructions and soaked my feet first. To make things a little easier, I went ahead and used a shaver on some of the larger calluses. Then, I went in with the callus remover. My bright idea was to sit on the edge of the tub and do it so I could just easily wash everything off when I was done. I waited a few minutes and started scrubbing and sure enough, everything easily came off and my feet were left super smooth.
Now comes the part I wasn't anticipating. This stuff makes surfaces slick; skin, bathtub, I'm talking everything. This stuff also doesn't wash off very easily. I ran and ran and ran water into the tub and kept washing and washing and washing and it was like being covered in Dawn Detergent that refused to come off. So with everything being as slick as it was, I couldn't stand up for fear of falling. After about 10 minutes, I have to be honest, I started to panic. Thankfully I had a sugar scrub within reach and I basically dumped the entire scrub on my skin and the tub to see if it would help clean out the callus remover. It worked and I got clean and escaped the tub.
Will I use this stuff again? Probably not. It was mildly traumatizing and I have no interest in getting stuck like that again.
The stuff did work though!