Soak the silk item in pure white vinegar for 5-10 minutes (replaces the Soda Ash in the Soda Soak method. Vinegar is much easier on silk, but needs the extra heat to "fix" the dye.
Squeeze out the excess vinegar and tie silk in desired pattern or scrunch. You can also work while the vinegar is still wet; the dyes will move differently on wet silk than they do on dry silk. There's no right or wrong, do what you like.
Squirt, sponge, spray or brush on the colors as you like. As dye spreads easily on silk, you will use less dye than you would on cotton. A little goes a looong way!
Put the silk in a zip lock type plastic bag big enough to allow for the expansion of the steam. The heavier duty bags work best. Place in microwave at full power for 3-5 minutes. To prevent bag from exploding, stop microwave every 45 seconds (or when you see the bag expand) to let the steam subside. All microwaves are different so be cautious and if possible do a test first to see how your microwave behaves. Be careful - if the bag pops open, it will make a mess. You can also do this in glass jars or a microwave safe bowl that you don't use for food.
After the microwave is finished, let the whole thing cool before opening and rinsing and washing in Synthrapol.
WARNING! The bag and the contents are boiling hot! Opening the bag while hot might cause hot steam to fly into your hands or face.
The microwaving part of this method not recommended for children.