This is an alternative to using sux / sudox to allow you to use X apps after sudoing.
It's hands-off, it lets you use your normal su/sudo commands without any alteration.
Run visudo and add this:
Defaults env_keep += "DISPLAY XAUTHORITY"
In the normal user account (before you su to root), change your .bashrc to include this:
# avoid having to use sux/sudox when changing to root (this line cooperates with /etc/sudoers env_keep)
You'll have to logout and back in, before this will take effect.
[ -n "$DISPLAY" -a -e "$HOME/.Xauthority" ] && export XAUTHORITY="$HOME/.Xauthority"
This is somewhat tangential, but it's another way to make things convenient.
On your main X machine, add this to the bottom of your ~/.ssh/config: