I'm of the opinion (different to many of these posts, I know) but 'mechancial' means of cutting, scraping and peeling of skin makes it worse. The skin will thicken and harden becuase of the treatment, and will start protecting itself for the next treatment, like a callous on your hands if you're doing something repeditive like shovelling.
Eucalol Heel Balm Gold is the best I've found, sleep with the cream and socks if possible (hot climate might be prohibative?) and gently exfoliate with a good scrub. Also agree that shoes with a closed heel would be better than thongs.
Best of luck!