Absolutely. The only thing the method as described really requires is strong border lines between countries to make the Magic Wand selections.

@the931stsoldier: Sorry I didn't see your question earlier. My demo map used a random parchment texture that I looked up on Google. However, there are at least a couple of tutorials here to create your own parchment textures. Here are two, one for Gimp and an off-site one for Photoshop:

[Award Winner] Creating old, weathered paper using the Gimp