I have used Transferwise to pay my expenses in Argentina a couple of time when there was no difference between the blue and the official rate. The recipient received pesos from a local bank (I believe banco Francés), and he didn't see the transfer as an international one so there was no paperwork involved.
The exchange rate was good and the TW fee was maybe 1-3 euros per transfer (over about €100).
This was 1 year ago, if not more. Different government, perhaps different rules now!
