Authentic Thai kneeling mats, massage mattresses, bolsters, and positioning pillows are traditionally filled with Kapok. This is a very soft, hypoallergenic cotton-like fiber that is very resistant to mold, mildew, and any kind of moisture. The exterior of these Thai massage supplies can be 100% cotton or a cotton-poly blend. Either way, the recommended method is dry cleaning, and you can use any type of spray or wipe-off carpet cleaner for that.