Just Another GM |
Try here: Pathfinder Wiki Slavery
Some of the nations of the Inner Sea aren't mentioned at all, so they might frown on it, but not have outlawed it, or similar. They also might have been missed (Like Nidal, as an ally of Cheliax, they most likely allow slavery).
It should narrow the list of countries to check.
Depending the scale of your game, you might be able to just ignore some places as you might never go there.
Hope this helps