I've done it. It's a bit of a faff but I actually prefer handwashing to drycleaning as it doesn't make the silk bobbly.
Do it in the bath, so the fabric has lots of room to move.
First fill the bath with enough water so that you yourself could wash in it. Put in a mug full of salt in the water - which should be blood temperature and no hotter - to fix the dye.
Then put in a cap full of a silk/cashmere wash liquid (not ordinary non-bio) and wash.
Then rinse very thoroughly with clean cold water.
Then soak for ten minutes in the bath with a cupful of white vinegar.
Dry by rolling into a bathtowel, then flat near but not on top of a radiator.
Iron inside out whilst damp.