I have some Unger Fluffy yarn, and it looks like it would work. You might need to use a larger needle though, because it has a gauge of 5 stitches per inch instead of 4....or you could double it and use a smaller needle.
You never know unless you try. I got my yarn in an auction on eBay for a good price. It's acrylic yarn, so it's not expensive. It might not wear as well as the yarn for the original pattern, though. I would wash it with cold water, of course.
Here's a link to an example of Unger Fluffy in a sweater
Here's a photo of a skein of the Unger Fluffy in my stash. I'm using it to make a fluffy easter bunny.