A critical step to strengthening the ILO is to remove the power of the WTO to block enforcement of ILO conventions. But they should be held to some standards, especially for goods that are exported to developed country markets, often by corporations based in developed countries. Today there are effectively no standards. If people in a country democratically decide that they wish to produce for their own consumption through the use of child labor, and violate no international agreement to do so, and if no foreign corporations or investors are involved in such production, there may be little that anyone outside of that country has to say about it. But if such a country produces such goods for export, it is a different story.
Consumers have rights, and they have obligations.
If a consumer thinks that children should be in schools and not in factories, she has an obligation to avoid purchasing goods produced by children. This includes an obligation to support laws barring the import of such goods. And if foreign producers face lower standards for production to a given market, this will simply serve to undermine the standards for products in that market. It is far more likely that the imposition of such standards will replace some labor from the South with other labor from the South, e.g. replace child workers in Southern countries with adult workers in Southern countries. This economic determinism contradicts the political history of industrialized societies.