I've been selling antique and vintage doll clothing on Ebay for quite a number of years and the clothing I've acquired has arrived in all kinds of condition.   Some of the clothing is just too far gone and nothing can be done to it, i.e, mostly silks with complete melting to damage from mold, mildew, water, etc; however, alot of the clothing can be salvageable but needs to be treated carefully and very delicately.  My review will be on the clothing that can be salvaged.  Let's first discuss the whitewear dresses that seem to be the most common but this also applies to silks and this can also be used for the vintage patterned cottons just as well.  Most whitewear dresses are out of a lawn or a batiste fine cotton fabric.  Alot of them will arrive with stains from mold, mildew, old soap whatever, etc..   Not all of these can be taken out but alot of times they can be faded substantially.  First test the fabric to make sure that it is not weak so that it can handle being handled and washed.  If it seems sturdy, the first thing I would try is to soak one of these dresses by filling up a large plastic bucket, or better yet, a plastic dishpan with water and adding a chemical called Sodium Perborate you can get at a chemical store as well as online, or a name brand of this chemical is called Nancy's Vintage Soak you can also get online or at some antique or vintage clothing stores.  Another good soap to use is called Orvis.  This soap is actually used to wash horses and you can get it at a feed store or online.  Alot of the museums use this soap as it's delicate and the PH is not acid nor alkaline so it's alot gentler to the fabric. Most cleaners have high alkalinity in it that damages fabric so alot of the over the counter cleaners you get at the grocery store are just too hard on these delicate items. You will use a little bit of these cleaners at first and don't overdo it.  A good rule of thumb would be one tablespoon per two to three gallons of water but carefully read the directions.  Mix ONLY ONE OF THESE CLEANERS in with the water making sure that the cleaner is completely mixed in. Next, a dishpan is my choice, as I usually lay a washrag or dishtowel in the very bottom of the dishpan after I've mixed the chemical into it.  I will take my dress and lay it flat into the water so that it floats down onto the dishtowel in the bottom.  I will not agitate the dress, wring the dress, nor do anything to it at all.  I will let some dresses soak up to three days like this gently agitating the water and maybe moving the dress up and down gently in the water using the dishtowel, not touching the dress. If the dress is absolutely filthy, and the water has turned brown, gently pick up the dress with the dishtowel, dump the water out, rinse the dress off, and add clean water and add more of the chemical and put the dress back in.  O.K. you have left the dress soaking in the water and you've pulled it up a couple of times and it's starting to look pretty good to you.  It's time to take the dress out.  Use the dishtowel to do this as touching delicate wet fabric can cause it to tear.  Fabric is at it's most vulnerable when it's wet so handling it carefully and as little as possible is the best way.  Now dump your water out and clean the dishpan really good to get rid of soap residue.  This is the most important part of all is the rinsing of the dress.  First rinse the dress off really good under the faucet or use the sprayer so you get rid of as much soap as possible.  Fill the dishpan up again with fresh water and put the dress in it.  You will do this as many times as possible to rinse the dress out completely.  What alot of people don't realize is that the yellowish color you see on alot of the antique dresses is really from old soap that wasn't removed from the clothing so rinsing out the dress is the most important part. When the dress is finally rinsed out you will now pat it dry with a clean washrag, towel, or something absorbent. NEVER WRING OUT A WET DRESS.  Do this until you've taken out alot of the moisture.  Carefully remove the dress away from the dishtowel and you should hopefully be able to handle it directly. Next lay the dress flat so that it can air dry. I have several wooden racks at my house I got at a discount store (Wal-Mart) that I use for this purpose. They fold up easily and I keep one on top of my dryer I will hang dresses on that is completely out of the way.  Another good idea is to have a fan gently blowing on the dresses that hang over the wooden rack.  I leave them there until they are dry.  Lastly you are now ready to iron your dress.  It should look pretty good and fresh.  I do want to mention for those really stubborn stains, you can add a little bit of an over the counter product called BIZ to the wash if the dresses are sturdy. Make sure they are of a sturdy fabric. Don't put BIZ directly on the stain, mix it in the water with the cleaning agent.  BIZ, if used conservatively, really brightens up a whitewear dress. Be careful using this on any other fabrics other then cotton as old silk is so delicate and doesn't do particularly well anyway when washing it. As far as your silk dresses go, you can pretty much follow this formula being extra careful when handling the dress as old silk can literally melt or disintegrate before your eyes when put in water.  Silk that has damage to it; i.e, holes, melting is not a candidate for washing in my opinion. Silk that has been exposed to mouse droppings (storage) in particular, will not hold up well in water, so if you think that is a possiblity I would not try to wash it or expose the dress to water. On my sturdy vintage cotton print dresses, I will usually put in 4 or 5 dresses in a bucket and do the same way.  I will leave them in the water soaking for two or three days, dumping out the water if it's filthy.  I usually use a wooden spoon to stir the dresses in the mixture throughout the day.  Good luck to you and hope this helps freshen and rejuvenates some your old clothing.