In theory they should work if they do the job correctly. When you 'delete' something all it really does is mark the space on the hard drive where the file(s) are located and marks them as unused. So when you next want to place a file over it will just write over it. This is why people have problems clearing hard drives of data because it’s not actually gone.
So if the program is a good one and it has been made correctly then it should just work fine. Whether any of them do work I don’t know, I’ve not tried any. I even think if date is over written on the hard drive it can still be retrieved.
Hope my information has helped you
Venney
