Basically, when you sweat you produce bacteria that ends up on the inside of your pants - if you don't wash them this bacteria will eat away at the cotton and weaken the fibres making them a lot more prone to rips and tears. You will see that most, if not all of the Japanese denim bosses will tell you to wash your jeans often. The whole 6 month without wash thing came in with Nudie and it just goes against what wearing your jeans is all about. Remember, at the end of the day they're pants - wear them as long as you would wear any other pants and then throw them in the wash. Washed or not they will still fade and in my opinion they'd look a lot neater without those tears. When washing them, there are a bunch of different ways to do it. Personally, I tend to give my jeans a good soak in detergent every few weeks depending on how much I've worn them and a wash after a month or two. Again, this is depending on how they are worn - if it is the middle of summer and you're sweating more than usual then soak/wash more frequently.
