Sorry I didnt have time to answer this yesterday Matías.
Devaluation has two types of effects: direct and indirect.
The direct effect is on creditors/debtors with accounts linked to foreign currencies. In this case it favours borrowers and sucks for lenders. This is can be an exogenous effect on internal credit depending on how tightly capital is tied to the foreign exchange market.
The indirect effects (which are far more significant) have especially to do with the labour market. As the peso devalues it has a double effect: Argentine exports become more attractive, and foreign imports become more expensive. The result of both of these is the development of internal industry, which inevitably improves the labour market: with lower unemployment, real wages go up, employees have more leverage, etc. This in turn leads to more people with more money in the domestic economy (more internal demand) and the effects multiply. So the devaluation has the opposite effect of what you mentioned: it leads to higher real wages.
This is the way all developed economies have always been able to grow-- by fostering internal demand. The examples are everywhere: South Korea in the 70s/80s, West Germany in the 60s, China right now, the US in the 19th-20th centuries...
On the other hand, the idea of having cheap salaries in order to compete has inevitably turned out to be a drain on the economy, as it leads to capital flight. Just look at El Salvador, Haiti, Cambodia, Bangladesh... They get foreign investment, but their overall economies are worse and worse because there is no internal demand.
Does that make sense?