I would be careful about sending pesos from WU to a friend's Argentine bank account. From what I have been told you are allowed 55,000 per month into your bank account. After this AFIP will come after your friend. They might be hit with a tax bill at the end of the year. But this was something I was told, so it is not confirmed. Maybe someone has more concrete information about this. I would imagine that one transfer shouldn't cause too much trouble, but sending every month might create a problem.