You should find a tag that lists the proper method for cleaning the bed. It is likely attached to 1 end of the bed. The label may suggest that the bed be cleaned only by a dry cleaning service. If so, contact a dry cleaner for pricing and services.
Torn areas will allow the feathers to exit the bed during the washing and drying. Mend any damage or tears before continuing to clean the Featherbed.
The weight of the items will pound the bed and keep the feathers from sticking together. This will help retain the fluff.