Turn the feather bed daily or every other day. This is a traditional method of keeping the feather bed fresh by making sure that the feathers are routinely fluffed and turned.
Shake out the feather bed. Ask another person to assist you by grabbing the other end of the feather bed, and then together, shake out the mattress vigorously. This allows you to shake the bed more thoroughly than you would just by turning it, and it can be handy with beds that have not been turned recently.
Spread your feather bed outside on an old clean sheet on a sunny day. This allows the mattress to air out.
Sprinkle baking soda on the surface of the feather bed and allow it to absorb the smells for 24 hours before shaking it out.
Contact a dry cleaner. Dry cleaners are able to clean feather bed mattresses without crushing the feathers or using moisture that will cause the mattress to mold. You may need to call more than one dry cleaner due to the fact that some more modern dry cleaners do not have the facilities for this service.