There is a major flaw in economic logic here. Yes - Chinese labor conditions are bad. Unfortunately, if we boycott companies that use Chinese subcontractors, there will be less demand for Chinese labor, which will reduce the number of available jobs, thus reducing their salaries, and making their labor conditions even worse. A shitty job is better than no job.

If we spend more money on foreign-made goods, we provide more demand for their labor, and effectively increase the available labor options for foreigners, which improves their labor conditions.