Recovering data from SQLite .db File Data
Community wiki answer:

Is it possible that the text appears in deleted rows whose disk space has not yet been "recycled" or "garbage collected".  If you vacuum the database and check again with grep, the text should be gone.


  I now need to find the best way to attempt to recover instead of vacuuming.


To recover the data, instead of vacuuming, make a copy of the database as it is now, look for a hex editor, and see what you can salvage by hand.

See also Undelete accidentally deleted records in Sqlite3 on Stack Overflow.