Necessities:

• 250 ml of liquid detergent
• Your regular detergent
• 125 ml white vinegar
• 150-200 grams of cleaning soda
  

This is how you make it:

Put all the ingredients in a container and mix it with about 700 ml of hot water. Put this mixture in the drum of your washing machine and do a hot load of laundry. Next, dry your pillows in the dryer or on a drying rack. After this your white pillows will be shiny white again!

Tip: you can of course also use this mixture for other types of white laundry! Think of a white duvet, white sheets or white towels.