I use Apple Cider Vinegar on my face after a workout. I apply it with a cotton round and leave it on to burn for a few minutes before I get in the shower. It's done wonders for my skin. It's a very mild acid so it helps burn off some of the dead skin.
You may want to dilute it with water if your skin is sensitive. Some people who use this say that it actually made them break out for the first week or two THEN their skin cleared up. I never had that problem though. Be sure to wash and moisturize your face with your usual products after you use it because like I said, it burns.