Oregano oil helps with abscesses but it takes time. The most effective way is to use Bentonite clay. Add enough water so it's somewhat solid and put it between the cheek and gum of the tooth with the abscess.
It draws out the puss and you'll even smell it in the clay. When that happens change out the clay. In a day or two (depending on the abscesses severity) the clay will draw it out. Much better and simpler than having your tooth pulled.