I tried many things to reclaim deleted data that were recommended but without success (this was due to the nvarchar(max)/LOB_DATA 'bug').
Eventually successfully managed to reclaim 17GB from a 30GB database using:
Use a SELECT INTO statement to transfer the whole table to a new table in a different database. Truncate the original table, and then run a DBCC SHRINKFILE statement. Transfer the data back to the original table.