On my vacation in Cuba some years ago, I found out that there are quite many westerners going there to learns Spanish in Cuban educational institutions. There were also university students who were there to participate in vocational education in Cuba-specific product manufacturing like rum. AFAIK even in Soviet times there were friendship programs and partnerships with the West to build civil ties which facilitated student exchanges etc, so I wouldn't be surprised if there are for DPRK too. I also recall something about joint programs with Korea/DPRK/EU/US to do production in special zones inside DPRK.

Except for Americans, the place was full of western tourists like me and my HSBC cards worked just fine. Those insulated places might not be as insulated as the general perception leads you to believe. The internet situation was PIA, though I hear its much better now.