If they are worried enough (that their boss has sent them a report to be checked by 4:30 or else) to open a doc in a mail, then they are worried / dumb enough to click through the warning (NB I comtract in Fortune 500 and every time I open my own excel file on my own desktop I have to click through three yes/no. It's no longer a defence)
Yea, I was waiting to see the "and to disable the warning" part of the tutorial. But to be fair, even though you or I would be stopped by the warning, most people wouldn't.
Really OLE needs to be deprecated and removed. It's ancient cruddy technology. It needs to die like ActiveX and <IE11
...and click through the warning.