I lifted this from the Adam's forum for cleaning Alcantara, etc. Dylan is really phenomonal about detailing. This should answer your questions:
HOW DO I CLEAN IT? 
Its  important to understand Alcantara does not respond well to most  chemical cleaners, as a matter of fact, many chemical cleaners will  actually discolor or change the texture of the material permanently  ruining the benefit of having such a nice material on the interior  surfaces of a vehicle. 
Daily cleaning and regular maintenance - I recommend the use of a medium-soft bristled brush, like the 
Adam’s Interior Brush,  to essentially fluff and renew the material. As you sit on the seat the  material will become matted or tired looking, a quick brushing will  revive the material and bring it back to life. Be sure to vacuum first  to remove and debris then brush in both directions. In the event you do  not have a brush a clean, dry, lint free, microfiber towel will work.
For a more thorough cleaning - Start with a clean, lint free, microfiber towel and spray a light mist of 
Adam's Carpet & Upholstery Cleaner  onto the towel. Gently wipe at any soiled areas or wipe the entire  surface if its been awhile since the previous cleaning.  NEVER SPRAY THE  CLEANER DIRETLY ONTO THE ALCANTARA!! Flip the towel to a clean side and  repeat as needed. 
After the surface has been cleaned use a 2nd,  dry, lint free, microfiber towel to remove any moisture and follow with  a brush to re-fluff the material. Its important not to use too much  product, a very light misting of cleaner onto the towel is all thats  needed.
BUT WHAT IF I HAVE STAINS?
Prevention  of stains is the most important thing to keeping an Alcantara surface  clean, but accidents happen. In the event you do spill something or do  notice a discolored spot the sooner you act the better. The longer a  stain is allowed to sit the less likely you'll be able to remove it.
In  the event you do get a stain, act quickly (within 30 minutes) and begin  treating the stain from the outside edge into the center in order to  avoid 
the stain spreading. Never pour a cleaning product directly onto Alcantara!!
Before attempting to remove the stain, remove any of the excess spill or substance that has fallen on the upholstery:
If its a very liquid substance like soda or juice use an absorbent towel, a 
waffle weave microfiber being ideal. You can also use a sponge or synthetic chamois (water sprite, absorber, etc.)
If  its a thicker substance, yogurt, milk shake, smoothie, etc. use a  spatula or spoon to scrape as much off of the surface as you can. If you  have a wet/dry shop vac use that to remove the excess. Avoid rubbing to  prevent the stain from spreading or going deeper into the material.
After  the bulk of the spill or contamination is removed use a white cloth or a  well wrung sponge for the removal of as much of the stain as you can.  If you use a sponge, rinse it in clean water and wring it well between  each pass. Try to wipe as little as possible, blot as much as possible,  apply pressure to get any liquid up into the sponge.
For the specific treatment of the different types of stains follow the instructions below:
- Fruit juice, jam, jelly, syrup, ketchup: Use lukewarm water, rinse by dabbing with clean water, rinsing and wringing the towel or sponge often.
 
- Blood, egg, excrement, urine: Use  cold water; avoid warm water because it makes these substances  coagulate, rinse by dabbing with clean water, rinsing and wringing the  towel or sponge often.
 
- Liquors, alcoholic beverages, wine, beer, coke and tea: Use lukewarm water; if the colour mark remains, treat it with lemon juice and then rinse it well.
 
- Pencil, pastry, cream, chocolate, ice-cream, mustard: Use lukewarm water; rinse by dabbing with clean water rinsing and wringing the towel or sponge often.
 
- Hair gel, tomato sauce, coffee with sugar:  Use lemon juice and then wipe with lukewarm water; rinse by dabbing  with clean water, rinsing and wringing the towel or sponge often.
 
If the stain is no longer water soluble: 
Depending  on the type of stain start with the specific recommendations above.  (water or lemon juice) In the event these do not work pure ethyl alcohol  (available at most pharmacies) and follow the instructions below. Keep  in mind this is a method of last resort and should only be attempted if  none of the previous methods have worked.
Rub with ethyl alcohol,  then with water and rinse. Leave the vehicle in a dry environment with  the doors or windows open and allow the area to dry. Repeat the alcohol  treatment as needed or until there is no longer any improvement in the  stains appearance.