In his book The Naked Civil Servant Quentin Crisp famously remarked "There was no need to do any housework at all. After four years the dirt doesn’t get any worse."
The Herald is reporting that the same applies to denim jeans, only more so "Great news for students - jeans left unwashed for a year are no dirtier than those that have been worn for a fortnight."
There is, of course a gotcha ... the wearer's personal hygene becomes very important to the process and the jeans need to be aired.
Seems to me it would just be easier to wash them