This has been so funny to read on Superfuture.com with everyone contributing their experiences as to washing and drying their jeans. Here's the best I could find. It's called washing, Samurai style. Chicken says: "It begins saying that this is just one example of how to go about washing your denim, but by no means a definitive method. Since denims are personal, there should be personal styles of washing, too. Makes sense."
"Soaking: The guy demonstrating (they call him "Master") prefers a 42 degrees C or cooler, lukewarm water with a small tablespoon of salt. Some people prefer adding vinegar but most people don’t put anything in it. People believe salt will help get rid of the "glue" (I wonder if they mean starch and stuff) and extra indigo. At the same time, salt will help the main indigo to stay on the material better. So it says. And some people soak at body temperature. I’ve read in other places you’re supposed to soak after you turn the jeans inside-out, but Master is doing it normal, outside-out.
Make sure to take all the air bubbles out and let it soak for about 1-2 hours. Anything longer than that could be annoying to the rest of your household, but also unnecessary."
"Wash: Detergents without bleach or phosphate(?) are best to use, but sounds like it really doesn’t matter that much. Master used a detergent soap and swirled it in the water few times. The key thing is to make sure that the water’s not too soapy — it shouldn’t be foaming. Even with the non-foaming water, you’ll see that by the end of the wash the water has turned quite blue. It says wash is important because you get rid of oils accumulated during the making of the jeans. Oh and Master washed the jeans inside-out."
"Rinse: The key to rinsing is to rinse very well. Make sure all the detergent’s gone. Some people add a tiny bit of detergent at the end of the rinse cycle to add a little sheen to the jeans, but Master thinks that’s really stupid because it will hurt the cloth. So rinse."
"Getting rid of moisture: Try to use your hands and get rid of water BEFORE the washing machine gets into the spinning drying cycle. Denim, which is heavy to begin with, with water can spin in an awkward way inside a machine, which can, in the long run, cause some unwanted damage to the jeans. Definitely, do not twist. Which will hurt the denim, again. Instead, push and massage the moisture out. And don’t use the spin cycle too much. It’s not good for your denim."
"Drying: Master dried the jeans still inside-out. Make sure to get rid of the wrinkles, especially in the salvaged area before you hang it. Some people will hang it upside-down, but that’s up to the user. The best time to dry is morning ‘till noon, but as long as it’s in a place with a good air current in a shady area, it should work just fine. Drying it right in the sun is bad. It’s because the moisture in the jeans can “boil” suddenly and cause damage to the cloth. Air drying in a freezing weather is also horrible. Dryer machine is not a bad thing, since you can get a steady and controlled environment for the jeans to dry. But the downside is huge. Over-drying can cause an irreversible damage. So they can’t recommend it. Some experienced dryer machine users, though, have tricks using towels and/or tennis balls with the jeans."
"Extra: Master used mink oil on the patch when it was half dry. For long-term effect. I guess it’s kind of like baseball gloves. Master also recommended cutting off all the excess strings that come out after the wash. Some people prefer to have them fall off naturally, but that’s up to the user."
So there you have it. Some more tipe to think about when you dare to wash your jeans.