I have used the wool paper, and got very good results. However, I only use the thinner paper as a first layer as it moulds to the shape of the cast better, then I use 2 more layers of blotting paper or construction paper. I have made a mask using 2 layers of the Carta Lana with construction paper in between.
The finish on the mask is smoother than anything I have been able to achieve with other papers and looks like i'll have less finishing and sanding to do.
I use a fairly thin solution of watered down PVA glue on the Carta Lana to ensure it soaks in and then sticks.
Alan