Machine clean a yellow pillow
To restore the whiteness of the pillow, you can use the washing machine, which is simple and effective. You will need to prepare one cup of washing powder, one soda crystal, and one cup of bleach. After filling the machine with a third of the very hot water and placing the ingredients inside, it must be left running for a few minutes to allow a good homogeneity of the preparation.  Then you place the pad and program a 90 degree turn. Once the washing is done, it is best to place the pillow in the air and sun, or not and according to the label indications, on a proper dryer cycle. In fact, the ultraviolet rays of the sun have a bleaching power on fabrics.

It is entirely possible to prepare this solution and put it into action in the bathtub in the event that the pillow cannot pass through the washing machine. Hence, it should be left to soak overnight to enhance the effectiveness of the whitening on the pillow.
Likewise, if your washing machine has a slot, simply add the ingredients as you go, once the cycle has started at its highest temperature.

Clean a yellow pillow with white vinegar and baking soda
For an environmental solution, using white vinegar and baking soda will be very effective if the yellowing of the pillow is tolerable. Thus, you will use the same amount of a cup of white vinegar as baking soda in an amount of hot water to soak the pillow. After soaking for an hour, you can put it into the washing machine directly by selecting the 90 degree cycle.
If soaking, you will be sure to mix the two ingredients well and leave the pad for several hours to allow the preparation to work at its best.

Clean a yellow pillow with lemon
In addition to being an excellent bleach, lemon juice is an antiseptic. This environmental ingredient can be used in several ways to overcome yellow spots. It is possible to put the equivalent of two lemon juice directly into the detergent drawer of the washing machine before the cycle at 90 degrees.

In soaking mode, you will only have to add the juice of about ten lemons, in enough boiling water, to allow the ear to be completely submerged. Then, if possible, it should be washed in a washing machine.

Another solution is to add hydrogen peroxide in a 2 to 1 ratio. Example: 200ml of hydrogen peroxide to 100ml of lemon juice. Again, the entire pad must be covered to allow the preparation to work. Finally, machine washing will effectively complete your whitening session.