I have severe dry cracked heels I've been told by a doctor that it's fungus. Tea Tree Oil works fantastic but you have to be able to afford enough of it for the fungus to be completely gone. I've bought about $250.00 worth
(I used Thursday Plantation Brand) and I ran out before it was totally gone and you waste your money if you don't buy enough because if you run out it starts to come right back with in MINUTES. But if you can afford like $300.00 bucks (use your tax return money lol) you'll kill it for sure! Once your heels appear to look all healed keep using the (straight 100% tea tree oil) for 2 more weeks for it will fool you and come back if it is not killed/healed!!!
If it's just dry heels than probably any of these other ideas will work but TEA TREE OIL is a funguses worst enemy, and use a LONG, VERY BUMPY AND ROUGH PUMIC STONE, not those pathetic smooth pumice stones they sell at the drug store, they are a JOKE, you'll have to buy it like at a janitorial store or somewhere like SMART AND FINAL they work great! The rougher the better!
Use the T.T.O 3 times a day and then rub like Vaseline or garlic oil or some kind of greasy stuff like that and put a bag on your feet and then socks over that every night. Your feet have to have the T.T.O on them at all times. DON'T LET UP and be patient. :) I put the 100% T.T.O in a GLASS spray bottle and sprayed it on my feet, worked fantastic, until I ran out :/