Replaced a Material - Why can't it be Purged?

I’ve been replacing materials to consolidate them in my model. I use Vray to “Select Objects in Scene” (with that material) then select the new material, and then “Apply to Selection” which does a great job of a find/replace function. I then “Purge Unused” in the SU Material Editor.

90% of the time this works great.

The other 10% of the time the replaced material is “stuck” in my model and I can’t seem to purge it (I can of course delete it, but then I’m concerned it’s going to be a problem somewhere else if it’s still clearly attached to something).

I’m guessing that if there is a component in the model that once used that material originally that the material is forever bound to my project so long as the component is there. Am I right or is there a better approach?

No.

More likely that material was applied to a component or group container and then that object was edited and different materials were applied to the faces inside. Those face materials override the materials applied to the containers.

Or maybe those materials are used on a component you’ve deleted from the model space but haven’t purged.

Another possibility is the material is still applied to edges.

If Purging won’t remove them, they are still in use somewhere in the model. Try purgingunused components first.

Material Tools could be useful in removing those, too. It’s available in the Extension Warehouse.

In this case I sometimes just delete the material itself and let sketchup replace it with the default. Sometimes the swap is obvious and I can see where the undesired material was.