Methods
If you do not have access to a washing machine, you can try these alternatives:

Cleaning the spots: Mix sodium bicarbonate with water to form a paste and rub the yellowed areas with a toothbrush.
Sun-shed: After washing, leave the pillows outside in the sun in the sun. UV rays naturally whiten bleed bleeds.
For
Keep your pillows fresh longer:

Use pillow protectors under your pillowcases to add an additional barrier.
Wash your pillowcases every week.
Regularly vent your pillows to prevent moisture build-up.
Replace the pillows every 1 to 2 years for optimal hygiene and support.
Conclusion
With a little effort, you can restore your pillows to their bright and clean state of yesteryear. Regular maintenance and simple cleaning tips will keep your pillows fresh, extend their lifespan and improve the quality of your sleep