notochina.org
notochina.org
notochina.org
I imagine some of this data may be significantly difficult to source. But I would use such a site. You don't even have to be "political" about it. Simply expose the product metadata you have to your search engine and let your customers quietly know about it. I could see Amazon progressively introducing parts of this with little blowback.
Sadly, it doesn't seem likely that anything less than a full-scale boycott and supply chain pullout will ever make a dent on the human rights situation in any of these countries.