within two blocks of my house are two cuevas who will let anyone in, they just buzz you in- I entered both with no recommendation, no id check, just a casual glance. Now, I suppose I dont fit the motochorro profile, but I think its a lot easier to change money than you imply.
I was in Tandil last year, walked into a bank-like place on the main street, with big signs that said cambio, they gave me blue rate no questions asked.