An antibacterial soap is the best thing. You want it to dry out and toughen up so that it will be less tender and not open to infection, etc. At home, stay barefoot as much as possible. Make sure she wears socks to go out, but not the "stringy" kind until it roughens up some. She doesn't want it to scab over and trap a sock thread in there. I've had to pull some out of the meaty tissue and... well, it looks painful and bleeds.