Don't use ANY loose substrate with little ones.
Beardies in general like to lick/taste everything around them,
and little ones can be downright obsessive over it.
Walnut shells, ground wood (like the aspen substrate we use for our snakes),
sand, etc all are potentially dangerous for ANY beardie and are
especially big no-no's for little ones.
Use slate tiles, repti-carpet, or non-adhesive shelf liner if you want
something other than paper towels or newspaper.
I like the slate tiles, they are rough enough to keep sharp beardie nails filed down
naturally and they are easy to clean when poo'd on.