I guess I'm worried about staining the washer? Or something? It seemed like a huge blinking deal.
I decided not to splash out on real silk. (The original coat had its edges bound in silk, which then had goldwork couched to it.) If I do this over with actual wool in the future, maybe then. I bought a decent quality, lower-gloss polyester satin instead. I normally avoid polyester like the plague, but it's only going on the edges and hems. It shouldn't be too bad.