many wash them in a FLer, hot water, add some bleach....some pillows stay fine through the process, others will bunch up, and never return to their original shape...
I found it best to wash/soak them either in a bathtub or laundry tub....really warm water and again, a good detergent and bleach...…
place pillows in this solution, and squeeze the air out to allow the whole pillow to get saturated all the way through.....
usually best to start at a short end, and while holding under water, jelly roll it up on itself several times, squeezing out water, and allowing more to absorb.....
then let them soak for about 15-30 minutes.....
drain the water......and then add fresh water, repeating the same rolling/squeezing technique....several times until all suds are gone, and water is clear...…
a final spin in an automatic.....and about 15 minutes in the dryer, and your good to go.....
sounds like a lot of work I know.....but it has eliminated the bunching up issues