Removing unused dll?

I have merged a bunch of Turbosquid purchased geometry into my scene and it had a load of Brazil type materials assigned. I have gone through each object and made sure that all materials are Vray ones. However, when I send the job for a network render, it keeps crashing saying that there are dlls missing.

How do I clean the max file of all the brazil stuff? The dlls the file reckons it is using are ‘brazilcore.dlu’ and ‘brGlassMtl.dlt’

I’ve even tried merging everything into a new file with no luck.

Success - there was some unnamed material assigned to a bunch of events (whatever they are!) that were nowhere to be found. Changed the material to a standard and now it is OK.
Bloody Brazil!