Hello, this is Dr. Jess. Doesn't look like anyone else has answered your question, so I will go ahead here. I wish I could tell you there is a cheap at home way to fix an abscess, but it doesn't exist. The fact of the matter is, that antibiotics are required if that is what is going on with your kitty. I would get him in as soon as possible, because if t
he area is just swollen now and hasn't actually formed an abscess, it is possible if you get him on the antibiotic right away, the area will decrease just with that alone, whereas if we wait too long and an abscess forms, then it may have to be lanced/drained/flushed/etc. Here is an article on abscesses: http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=550
and another: http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=361
I worry with it being on his face, does he have something going on with a tooth? Sometimes we can get abscesses of hte tooth root that can develop swelling and rupture on the side of the face. Not sure where your kitty's issue is, but these are usually located on the upper cheek under the eye area. Be sure to ask your vet if this could be his issue, because if it is, then it will just keep coming back if the tooth isn't removed. As I said, not sure if this is his problem since I cannot examine him.
I wish you the best of luck! Let me know if you have any questions.