I had a professor who said he used to travel to Russia and the only thing he would pack were suitcases of jeans to sell.

I've heard many variations on that story before, but it was way back in the days of the Cold War and USSR. Apparently when the few Western tourists who ventured to travel on the Trans-Siberian Railway would alight for a temporary stop at a train station somewhere in the middle of no-man's-land they would be mobbed by Russians who would do almost anything to get hold of their jeans (seems many of these tourists left the country with a change of pants).

Bank then, the USSR establishment considered jeans a decadent Western culture and thus they weren't available behind the Iron Curtain except as contraband.

I carried spare pants and sneakers that would otherwise have been trashed.