Had an absess on left buttock. on antibiotics 3rd day. all pus has drained. now just an empty hole. how do i heal this? how long?

Abcess: This will fill in from below and will take weeks to fill in as it is a very slow process. I recommend keeping the area clean and rubbing the area around the hole with rubbing alcohol daily to kill any staphylococcus colonies that may inhabit the area and thus protect against other abcesses from forming. Keep a clean gauze daily loosely over the hole and keep in place with paper tape only.