I found a product called "Prid" that is awesome for boils, carbunkles, pimples, etc. It come in an orange tin with black lettering. The tin is about the size of a fifty cent piece, however it is based bit more than a quarter inch thick.
You can find it in any drug store or in Wal-Mart's Health and Beauty aids.
I get a bandage that is at least twice as big as the boil, put a clump of Prid right in the middle of the bandage, and cover the boil with it, tightly. The size of that clump depends on the size of the boil. I put at least as much Prid necessary for a thick pad of Prid on top of the boil. Don't puncture the boil or anything!!!. Trial and error will teach you.l how much to put on it.
After covering the boil tightly with the Prid Bandage, leave it there for THREE DAYS without uncovering it. On the third day, carefully remove the bandage and clean area gently with water dampened gauze. If the boil is anything more than just a pink patch of new skin, cover it again, just like before, for three more days. Continue this treatment until that area is healed past the point of new skin and looks pretty normal. The Prid won't do anything to skin that is fine.
ADDITIONALLY- Prid is the BEST for bug bites of all kinds, just treat the bites the same way!!
Prid is black, sticky, oily, and nasty looking. However, boils, carbunkle, etc. can't stand up to it! My mom had a carbunkle on her back that would never drain completely and kept coming back, creating a horrible infected... Thing. It took 12 days of Prid before we started seeing new skin.
Prid. Man, that stuff really works... Every time!