After the pre-wash inspection is complete, the first step is dusting. A wool rug may hold pounds of dry dirt that is not visible to the eye. Wool fibers have fish scale-like pockets which hold many times their weight in soil, dander, mites, and grit. This is not just “dirt”, but bacteria, germs, oils, and many other contaminants deposited by your feet.
Simply washing a rug full of dirt in the foundation and face fibers creates a muddy mess. This is why each rug needs to be dusted before it gets wet.