We had luck using the "green gobbler" cleaner (the normal one). I've also heard "enzymatic" cleaner might help (ex: "green gobbler enzymatic"--I'm not a green gobbler shrill I just ran into the name).
This after cleaning out the same drain like 10x with a snake, never seemed to quite clear it... (laundry drain). Even had the "pro" guy come and do it with his high speed (little) snake. It just got backed up again a few days later. I've also heard you can buy those high speed ones and make a little kink in the line 6" from the end and again 18" from the end, so that it kind of scrapes the pipe as it goes down.
Good luck!