It's not true. There were official import channels. Not many consumer goods were imported but some were. Secondly, there were shops where travelers (sailors, pi

It's not true. There were official import channels. Not many consumer goods were imported but some were. Secondly, there were shops where travelers (sailors, pilots, etc) could sell the goods they bought abroad. Thirdly, soviet people worked abroad, e.g. building plants, factories, power stations. These people were paid in special kinds of checks and they could buy foreign goods in a network of special shops (Berezka). I know this because friends of my mom worked on building some powerplant in Egypt (I don't remember exactly, but it was Middle East I think) and bought many things with those checks.