Had these before. No, they don't last long, but neither do the much more expensive versions. I admit they fall apart fairly quickly - I refer you to my previous comment. They are what they are - cheap odour eating in-soles. I'll buy them over and over.
My tip to the complainers - buy the expensive ones.
I don't mind having to change them every few weeks. At least they stop my shoes (and slippers) smelling. And that's what you buy them for.
I think they are excellent value for money and would recommend them to anybody.