I also purchased a couple of the natural sheepskin mitts from the Autopia store a couple of years ago. Fantastic mitt, that last so long I havn't had to open up the second one yet. A real quality product.
i am currently using a viking sheepskin mitt with no probs and also have some sm arnold & eurow mitts as well. naturally... i picked the softest, thickest ones i could find at the time of purchase.
The last couple viking mitts I bought both had serious shedding problems.. I bought them at the same time (from Kragen) so it could have been a weak batch, but it was disappointing to say the least.
My favorite washmitt is the jeff's werkstatt lambchop. It has a thicker pile than the Eurow mitt I have and the liner is much more durable. I also like the fact that it's thumbless so you can more easily use both sides.