Can spanish moss be replaced in a voodoo doll?

Spanish moss is often used in the creation of Voodoo dolls because it is readily on hand in the New Orleans area, and there is a lot of it. You use what you have, and if you don't have it, you improvise!
It is perfectly all right to use something other than spanish moss to create your voodoo doll. Voodoo dolls should be made to be uniquely personal toward the being or goal in which you are wanting to focus. And if you think another base material would be more suited to your purposes, go ahead and use it. :)