Any luck fixing this?
From what I've read (King Ranch website, click on details when looking at their leather conditioner), once a stain is in the leather, it is there permanently. Use a cotton towel with water to try to remove the stain quickly. Then just take care of the leather as best as possible, using a conditioner. I ordered the conditioner from King Ranch but I'm sure any saddle/tack shop will have similar products on the shelf.