Refresh/reload/clear references?

Hi, I have recently gone over a bunch of textures, replaced individual textures with combined textures for fewer load calls, etc.

But going over the old files to make sure they are no longer in use, my materials, particularily material instances insist they still use them, even though the parent’s dont.

How do I clean up the references to make sure I got everything?

If it says it’s referencing them, it is.

An instance can still reference something the parent isn’t.

The instance doesn’t have any special parameters that references the texture, that’s all handled in the parent, and the parent no longer references it. So, how to I refresh it?