If the welfare of the children is the actual end result that is looked for, then a nation's internal labor law changes are the only reasonable starting place. Children now, as in the era of Western industrialization, are sent to work to help support the family. It has always been this way on farms, or so our historians and anthropologists tell us, and the principle of child labor continued into the much more hazardous and grueling industrial era.
What ended child labor in this country were laws (legislated morality) prohibiting it that were enforced along with laws providing decent adult wages, labor conditions and work hours.
There is no reason to think that the solution to child labor in other countries will be brought about any differently: the countries with laboring children must make comparable legislated moral changes to their labor and wage laws. If, on the other hand, the objective is ease for the Western conscience, it is simply a matter of not purchasing items imported from countries with known child labor markets.