Sam wore the same shirt for at least a week! From The Rapture (4x20) to Sympathy for the Devil (5x01), inclusive. Seriously, not being able to change during When the Levee Breaks and Lucifer Rising makes sense, but if I were Sam the first thing I would have done once I was reunited with my brother and my belongings would be to change out of my dirty shirt...not keep it on for another 3 days.
That had to be one smelly Winchester.
In other news, I've now completed my own files for the If Clothes Could Talk project - so, now all I have to do is continue to post things incrementally. I'll update what I have posted so far with S4 either tonight or tomorrow.