Search for Blocks of text

We have all of our standard drawing notes as Blocks (.sldblk) and we just drag them hither and dither onto drawings as needed.
These blocks contain text referencing company specs and manufacturing practices.
This morning the Powers That Be (PTB) have decided to ELIMINATE a company spec. altogether. I have been charged with finding every instance where that note may have been placed.
I'd sure hate to go back to the PTB and tell them it can't be done. Conversely, I'd really like to look like a hero to the PTB by making it look easy.
The Block files (.sldblk) are in the PDM Workgroup vault. I've isolated the one with the offending text and searched the 'Where Used' in the 'Document Information' to no avail. It simply doesn't register anything at all. It appears that SW doesn't track Blocks.

Is there any successful way to search the vault for specific text on drawings?

SolidworksDrawings And Detailing