In case someone has trouble with this: A way to add brew apps to a path invokable by a gui is by exporting the environment variable path in /etc/launchd.conf:

# /etc/launchd.conf
setenv PATH /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/Users/yusuket/bin

You need to add the /usr/local/bin for brew's apps.

THEN make sure to restart you machine. Logging out and logging back in won't work.

And you're done! Now you can run your brew executables from GUI apps in Mavericks.