We have listed some of the common stains happen on your silk linen, and what if others? Deal with perspiration; you could use diluted ammonia (equal part of ammonia and water). Rinse well. And others like Oily or Greasy Stains try some liquid dishwashing soap letting it sit for few minutes. Rinse with water. There are still many for both of us to find out the best solution for it.
But not all silk is created alike. There are many different kinds which mean that a method that removes a stain on one type of silk may not work on another type of silk. Always test the method on an inconspicuous section of the sheets first, like on a corner of the fitted sheet that does not show when it is on the bed. All in all, keep your great silk duvets clean and there won’t be so much trouble for you!