A guy who goes to church with me had a boil on his back. He tried hot compresses and said it drained but came back. Finally, he started running a fever and went to the emergency room. The ER doctor looked at the boil and said he wasn't touching it, that he was sending the guy for surgery!
In three hours, my friend was in the OR, and the doctor had to cut away quite a bit of infection. My friend said the doctor told him he was on his way to a bloodstream infection, and should have seen his doctor when the boil returned.
Home remedies do work, but you need to see the doctor if it doesn't go away or you start feeling punk or running a fever.