You can't dry out a pumpkin. Lots of stores (K-mart, Target, Wal-mart, various craft stores) sell fake pumpkins for carving and decorations. The only "pumpkins" that I can get to dry are hybrid pumpkins from a cross with gourds. Sometimes pumpkin patches have them in their fields. You can tell them apart from other pumpkins because they are usually bumpy or aren't the standard orange color. Basically the overall shape looks like a pumpkin but otherwise it looks like a giant gourd. And of course all you care about is the shape, since you won't see that it had green stripes or whatever when it dries.