In this case it's up to merchants actually creating an economy for the alternative driven by it's stability over that of the "normal" national currency. There will always be the option of conversion, that is normal and should be expected. In the situation of a rapidly devaluating currency the relative stability of Bitcoin can be an asset to it's use of a currency ( but it is depreciating so this is why my suggestion of SBD with it's peg can be of a further increased utility). The stability of crypto over rapidly inflating national currencies is a strength for pricing of goods as 1 SBD will hold its value much longer then a Venesuelan bolivar.