Finding materials that re missing an image texture for PBR (not pink)

I have several materials in the same scene that share a few grunge maps. These grunge maps are mostly used for roughness and normal height.

When I unpack the textures there are several copies of the exact same grunge map. ie grunge.000, grunge.001, grunge.002 etc.

I think to save space and ram that they all could share that same image texture. When I delete all the copies, I then have to manually replace them within the materials.

The issue is, I cant figure out which materials need to be re directed to the grunge map. Since these are not plugged into the diffuse, the materials do not turn pink. therefore, I cant tell which ones are missing the grunge maps without dissecting each material.