Do not use a shampoo. Use a washing up liquid such as DAWN fish soap or Fairy Liquid washing up soap. If you do not have these check with your local wildlife folks to see what they use to wash waterfowl during oil or chemical spills. Make sure you thoroughly wash it from the feathers so that it does not stay on the bird.

Dry the bird and keep it inside for several days with food. Let the swan dry and preen itself so that it can replace its natural oil so that it can stay warm and water repellent. If you release it before this happens the swan can drown or get sick from not being able to keep warm. The Regal Swan