I know the rough heels problem well. I hate shoes and only wear them when being barefoot would not be socially acceptable (or they're six inch platforms and I'm poling) so I am somewhat prone.. When it's a minor case I usually just use a pumice stone on my heels when I have a shower. But when they get really rough or cracked sometimes it isn't enough.
The one thing I've had work and seen work for other people is this heel cream called Eulactol here in Australia. It's an Australian-made product so you'd either need to order online from an Australian online pharmacy, or find something with similar ingredients in the US. From what I read, I think urea is the main active ingredient, but here's the ingredient list I found online:
purified water, urea, lanolin, petrolatum, decyl oleate, dicoyl pentaerythrityl distearyl citrate, propylene glycol, microcrystalline wax, dimethicone, glyceryl oleate, carbomer, triethanolamine, aluminium stearate, methylparaben, propylparaben, butylparaben, ethylparaben, propyl gallate, citric acid, bha, fragrance.