Is somethng like "Mr pumice" pumi bar suitable? I personally use this on all my pedi clients.
They can be cut to size and disposed of after every pedi if thats what you want to do.
Or they do a very small one that is disposable in a pack. These are from sally's salon services.
Depending on my client’s needs, I use a guarded razor (I dispose of each blade in a sharps box), then Love pumice (which you can buy on Amazon it AliExpress) then a double sided pumice stone, then a foot file. I sterilise everything else in Milton/sterilisation solution. It keeps my overheads down, is hygienic and a very effective combo!