PrivaZer is definitely more secure by default when it comes to wiping/erasing your data. However, I believe it focuses on cleaning Windows temp files rather than personal documents, although it should still be possible. If you do decide to try PrivaZer, read the first run wizard very carefully as it may offer to disable features of Windows.
Then you can try recovering your data with Recuva,
https://www.piriform.com/recuva . Overall, PrivaZer should do a better job than CCleaner, even though both products offer secure erasing. CCleaner does not by default.
Eraser is another product, but hasn't been updated in 2 years so support for Windows 8 may not exist. Here's the link,
http://eraser.heidi.ie