How to hand wash your scarf in nine easy steps:

  1. Fill a sink or large bowl with cool water.
  2. Add a small amount of mild detergent to the water and create suds.
  3. Submerge your scarf fully in the water. Knead and squeeze it through the suds until it’s totally wet.
  4. Let the scarf sit in the water for around 15 minutes.
  5. Drain or pour out the water.
  6. Rinse your scarf by holding it under cool tap water. Squeeze and run it under the faucet until the water runs clear through the scarf and there are no suds left.
  7. Squeeze water out of your scarf – be gentle! Don’t wring the fabric too hard.
  8. Lay your scarf on a towel and roll the towel; this will eliminate a good amount of dampness so it can dry.
  9. Unroll the towel and lay your scarf on a dry towel to completely dry. Never hang a scarf to dry – this could damage its fibres!
 

Source: http://www.scarves.net/blog/how-to-wash-a-scarf/