There is a lot of misleading information on the internet in relation to the deletion and destruction of data. Some of this is due to confusion in language, e.g. the difference between wiping and deletion and some of this is due to urban myth.
Below is a video, taken with the popular computer forensics tool EnCase.This video shows what happens when a single wipe is used on a drive. Not 2, not 8, o32, or any of the other “recommended” number of wipes. Just a single, simple, wipe.