I had a well a couple of houses ago, and cleaning out the dishwasher/washing machine won't do much for getting rid of brown on your dishes and clothes. What you really need to do is treat the water before it gets to the "user end." There are units available, and IIRC they're expensive. The problem is dissolved iron in the water and not "rust" from pipes (most pipes are copper anyway, unless you have plastic).
Any of a number of the substances mentioned in previous posts will clean up the interior of the dishwasher, but will not solve the underlying problem...
HTH,
Steve>>:kermit: