I had the girlfriend throw up in the my Audi once. She got the window open, but it made it in between the door and the door panel, as well all down the seat belt and seat. I ended up soaking EVERYTHING in baking soda for 24 hours, than repeated with a baking soda and white vinegar mix followed up with leather conditioner. I ended up pulling the door panel to get the rest of the puke out.
Baking soda will work though, make sure you use a lot and vacuum it out after 24 hours.