Washing feather pillows is important because you want to keep your pillows free of allergens such as dander and dust mites. Fortunately, pillows can be cleaned in the washing machine (although as with anything, check the care tag instructions attached to the pillow.
First, wash in the washing machine. Remember to wash only one at a time. The wet pillows are very heavy and can cause balancing issues if you do more than one at a time.
If your washing machine has a setting that will allow an extra spin session to get as much water out as possible, do that.
After washing, using many heavy clothespins, attach your pillow to a line outside and fluff regularly so the inside can completely dry. It may take 2-3 days to fully dry depending on the temperature and climate.