Evidence Eliminator works well for me if you don't want the data back at all and will run in the background.
If you have that many files to delete you might want think about running E.E to do a system clean, fantastic for getting rid of unwanted files cookies temp files ETC.
I have tried many solution ..
Best I have found was to take a backup of entire partition using sector by sector backing software (e.g Nortan Ghost, True image[use booting from CD/USB with harddrive speed at max 3.0 gbps etc]) later using backup explorer copy only required folder/files..
Make sure you after backup you check integrity of backup file..before formatting original partition
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