I have just heard from my silk supplier in China that the silk pillowcases I manufacture and sell wholesale and on line are completely machine washable.
The only safeguards are the following:
Wash on a gentle cycle on your washing machine
Keep the temperature to 40C
Do not use an enzymatic or alkaline soap. I recomend a gentle soap, mild shampoo or a wool wash product. After all silk is a protein so you do not want to destroy this property and subsequent benefits.
Handwashing though takes no time at all especially as you do not have to wash silk as often as you do other fabrics as silk naturally repels soil and dirt
You do need to iron and once again I have tried it with a hot iron and even with steam. You only have problems when you use a hot iron with polyester or nylon. It is surprising how much heat silk can take.
I do hope this helps those of you who love the feeling of silk next to your skin and also the benefits of it. Silk pillowcases makes your hair glide over the pillow and eliminates bed hair and facial wrinkles.
I would love to hear your stories on silk pillowcases.