Hi, Kent. I haven't done any more work on this, because I still think "borrowing" a real one to paste on is the best way to go. The second best way is like what Chuck Gardner wrote in the referenced thread. Looking at it again this morning, the only change I would make to his steps is to:
1. Increase the Canvas Size. Try 112 percent on the short edge, 108 percent on the long edge. Duplicate the background layer.
2. Select the Brushes tool and the Brushes palette.
3. Pick a brush to make the "mess." I tried the Dense Stipple 12. Obviously size can be changed later.
a. Double click Shape Dynamics and play with the Size Jitter and the Angle Jitter.
b. Double click Texture and play with the blend Mode.
c. Double click Other Dynamics and play with the opacity and flow sliders.
d. Experiment with other dynamics, including color if you wish to have a blend of two. I used black and yellow on one of my loops, but a sepia brown might be good.
4. Use the "Rounded Rectangle Tool" to make a path around the inside edge of the image. Start with a radius of 10. Make sure the "Paths" button is depressed along the top toolbar.
5. On the Paths palette flyout menu, choose Stroke Path>Tool: Brush.
6. Sometimes the stroke doesn't go all the way around. There are many ways to cheat around that, or just leave it that way. If you like, you can change brush dynamics, colors, etc. and stroke the same path again.
7, Delete the path and repeat steps 2 thru 6 for another path outside the first, perhaps with a little higher path radius.

You can use snapshots along the way to mix and match, the smudge tool, etc. Save any good brushes you come up with! Hope this helps. Once you have brushes made and saved, you could record an action to do all but the path selection, which you would always want to do manually anyway.
Best regards, Bill
http://www.pbase.com/image/21201802.jpg