Cleaning Sheepskin:

—We recommend applying Cloud Nine Water and Stain Guard to the outside of your new slippers before wearing them into the elements (or the kitchen!) 😉.   Be careful to not spray the inside where the Sheepskin is!  
Spray the suede side of the skin before wearing your new sheepskin shoes.  
Make sure you don’t spray too closely—keep the can 9” to 12” away from the slipper or boot.  Not doing so will cause the spray to puddle, not dry properly and change the color of your shoe in that spot.   Allow a few minutes to dry, then spray again and allow 30 minutes before wearing for the first time.  You should spray again each season, more if you are wearing them daily in gooey conditions or wear them while cooking.  If you're like us, you’ll wear them as often as possible!  Don’t even ask me to confess all the places I wear my slippers! 😮
Make sure you use only spray protectant made for leather and suede products. They are free of silicone which clog the pores and prevent the skin from breathing.
Follow the directions on the can

— Scuffs will probably happen, but don’t be sad.  Just take a brush (it can be a suede brush, or fingernail brush, even a toothbrush works) and gently brush back and forth over the scuffed area.  If needed, you can use a white pencil eraser to remove the scuff, then brush the area to remove left over bits of eraser.    
You can also try a bit of white chalk on any dark marks.  I freely admit to usually just rubbing gently with my finger on watermarks but if you feel squeamish at this idea, use your brush.  If you need to, you can add a few drops of water to the brush. 

 — If you’ve done a really good job of making a stain, add a little dab of Cloud Nine Shampoo to your water and brush and spot clean your slippers.  (WooliteTM is not recommended).  Rinse well with clean water, then blot as much of the moisture away as you can with a shammy (super absorbent Viscose rag) or other soft cloth.  Let your slipper air-dry.  If you get them wet all over, they will shrink up a bit, but never fear, after a short time of wearing them, they will mold to your feet again, and feel fabulous. 
OK, THIS IS IMPORTANT: Please note that if you fully dunk your slippers into water they will take up to 3 days to air dry.  It may not be real to you while you are reading this, but until you have worn them just take my word for it, you will not want to be without them that long.  Never put them into a dryer, unless you only use air.  Never leave them in the sun or next to a heater; doing so will likely damage the sheepskin and render them hard and shrink.   

— When the fur inside has absorbed too much transpiration and dirt, it is time for a good shampoo in the sink. Soak the product, use tepid water, ideally some sheepskin shampoo from Cloud Nine to restore the lanolin (or some mild detergent such as baby shampoo - it works to clean the skin, but the sheepskin shampoo has the advantage of restoring more lanolin) and then let them dry. Again, it will take up to 72 hours, so don't do it before the day you want to wear them. Do not put them into a dryer or where the sun will heat them through a window.

Sheepskin Longevity:

— Contrary to what one may think, the Soft Soles slippers will last longer than slippers with a rubber (TPR**) sole. Everything will eventually wear out, even though sheepskin slippers last “forever”, and the beauty with leather outsoles, a shoemaker can stitch a new piece of leather on the bottom when it does wear out, while rubber soles cannot be repaired!

— the insoles will be what wears out fastest. To keep them feeling nice longer, a little care will go a long way. Sheepskin insoles will eventually compact. When they do, pull them out and sprinkle baking soda (dry), scrub it in, shake it of and voila, good for a few more days or weeks (depending on how many hours you wear them per day) of fluffy comfort.