How to clean mud stain on cashmere

Let the mud dry, then brush gently. If the stain persists, dab it with cold water and Marseille soap using a paper towel.
Rinse with cold water. Repeat, if necessary, before washing in a "wool cycle", according to the garment's care instructions. Reduce spinning (max 600 rpm) and use a detergent for delicate textiles.
If the stain is tough, apply ammonia water (1 tablespoon per 1 litre of water), massage gently, then rinse with cold water, before washing in a "wool cycle" with reduced spinning (max 600 rpm).