You don’t need to go to Uruguay. This problem has long been solved, no need to reinvent the wheel.
You find people here who will give you dollars in the US against dollars here. That can be friends with the opposite problem, or people who provide this service for a fee.
If pesos are involved, those are converted to USD at an agreed upon rate - a normal rate - and life goes on.
A fee may be charged, but a small one - very rarely over 5%, and nothing close to the 14-15% you seem to think people will pay for jumbling the whole thing into a single operation.
As I said, there are ways things are done here. People who have this problem - lots of pesos to get out of the country - are normally already based here to some extent, and know how it’s done.