Microfiber is a man-made fabric typically constructed with polyester and nylon. It is lightweight, but still resists wrinkling and withstands everyday wear-and-tear. For this reason it is a common choice for upholstering furniture. While cleaning cushions in a washing machine is usually against the care instructions, microfiber cushions are the exception.
Cleaning Cushion Covers
If the case of the microfiber cushion can be removed and washed separately from the pillow, it is safe to wash the fabric in the clothes washer. Remove the cover and put it in the washer with a like-colored load of laundry and the usual amount of detergent.
If the cushion is inseparable from its cover, examine the care label and follow those instructions for cleaning. Generally, a foam cushion needs to be washed by hand to avoid the risk that the foam will break up in the machine. This is best done in a large sink or bathtub using mild detergent and warm water. If the cushion is polyester and fits in a washing machine, it is safe to do so -- but only on the gentle cycle. In either case, dry the cushion on the machine's air cycle or outdoors on a warm day, making sure to flip the cushion over every hour or so.
If the cushion just has a stain you want to clean, the number one rule is to dab, not rub, the affected area. Attempt to do so using just a clean rag or towel at first, then dab at the area using rubbing alcohol or vodka if necessary. This can take several tries; be sure to let it dry in between. Try to remove stains as soon as possible after they appear.
Too Much Washing
There is such a thing as washing a microfiber cushion too much. Keep in mind that fabric softener can clog the pores of the microfiber, making the fabric less likely to resist stains and spills with each wash. Professional cleaning companies know how to best handle microfiber cushions, so consider calling one in your area if you find yourself needing to clean the cushions regularly.
Microfiber is more heat-sensitive than other fabrics. For that reason, do not use heat to dry the cushion. Whenever possible, choose to air-dry it rather than toss it into the dryer on "low."