Forwarding X-windows through a su - session

I'm trying to forward my X windows, but seems to be limited to just on session? What I'm trying to do is invoke x-applications as another user, through a sudo su -. If I know the other user's password, than this is easily resolve with: ssh -Y user@host password: ******** gedit & However, if running a user which I do not have a password (weblogic, for example): ssh –Y me@host xauth list sudo csh (now root) xauth add (last line of the xauth list above) gedit & HOWEVER, I'm having trouble allowing another user to access the x display: xauth list su – weblogic xauth add (last line of the xauth list above) gedit (see if gedit launches). This fails. I've also attempted to go direct to the to the other user via sudo: ssh –Y me@host xauth list sudo su – weblogic xauth add (last line of the xauth list above) gedit (see if gedit launches). This too fails.