Watermarks can sometimes be removed by an acid rinse (i.e. low ph). I believe corporate has told me our orange deodorizer can qualify for this, but you may want to call them and double check. Key with silk (and also cotton) is to evenly distribute moisture and also to get them dry as quick as you can. We have cleaned silk before. If you aren’t feeling comfortable with it, see if there is a rug (only) cleaner in your area that you can partner with where they give you a discounted rate. Rugs can be a great money maker, but they are also extremely expensive to replace and have many “quirks” about them due to being made around the world by different people/methods that if you don’t notice beforehand, you may have an unhappy customer in the end.