According to the Ugg Australia website, a washing machine is no place to clean your Uggs. While the washing machine may be a convenient option for cleaning your boots, the harsh tumbling inside a washing machine could seriously damage them. Sheepskin may fade, stretch or even tear inside the machine. Knit boots may stretch, snag, pill or tear. Take the time to observe proper washing procedures for your specific Ugg boots instead of opting for a quick wash in the washing machine.
Ugg recommends its sheepskin cleaners for the best and most gentle cleaning of your Ugg boots. Products include mild soaps, gentle stain "eraser" sticks, inner-boot-refreshing spray and spray protectants to prevent further soiling of the surface of the boots. However, a mild detergent such as baby shampoo or dish soap is also acceptable as a cleaner. Regardless of whether your boots are sheepskin or knit, Ugg care products or a mild detergent are the safest products for cleaning your Uggs.
The Ugg Australia website recommends using cold water to thoroughly wet the surface of your sheepskin boots. Then, create a solution of equal parts cleaning liquid and water. Use a clean, wet sponge to apply the diluted liquid to your sheepskin boots, gently scrubbing the surface of the boot. Never scrub aggressively or apply undiluted detergent directly to the surface of the boot to avoid damage. Rinse the boots thoroughly with cool, clean water and stuff with paper to retain their shape until the boots dry. Apply a sheepskin protectant to the boots, then fluff the surface of the boots with a suede brush and remove paper before wearing again.
Fill a sink, tub or bucket with cool water and a mild detergent such as Ugg Cleaning and Conditioning liquid or dish soap. Place the boots into the water, allowing them to become thoroughly saturated. Use the surface of the knit boots to scrub one another gently until the boots are cleaned. Rinse the boots thoroughly in cool, clean water. Stuff the boots with paper and place them out of the way until they have dried (approximately 12 to 24 hours). Remove the paper and wear the boots as usual.