Nope. You want a standard GI Web Sling. Here's one I found on Amazon, but there are probably cheaper ones if you shop around, such as the one on the Appleseed Store. Appleseed is generally pretty flexible about equipment, but the GI Web Sling is pretty core to the instruction and is the closest thing to a "mandatory" piece of gear that you'll need for an Appleseed shoot.

Also, if you haven't seen it yet, read through the How to Prepare guide on the Appleseed website