I have always used peat moss but it wouldn't hurt to experiment with the moss on a small project. I used to throw in some of my husband's leftover sawdust, and the projects were fine. On the basket...I love using baskets as molds. Just cover your basket with about three or four plastic bags. That will not only preserve your basket, but add strength to the lightness of the basket. One of my favorite hypertufa fountain bowls is molded from a large basket. I've probably used it 20 times and it stills sits in my house holding magazines. Go for it!