[Nuslos]

I'm formatting my hard drive, also will this method make it appear if the hard drive has never been used?

[Gossamer]

Well, i recently did a 1 pass zero-all format on a 60 gig drive and it took maybe an hour or so, so a 7 pass should take 7 times that on a drive of comparable size.
But if the hard drive has never been used, you shouldn't need to do a 7-pass zero on it, just go Disk Utility > Erase and choose Mac OS (Extended), then it should appear.

[Nuslos]

I'm actually intending to make the drive data look as if the drive were empty or just new. I want to do a 7-pass to completely erase all data irrecoverably.

[BLAZE_MkIV]

Get a hammer.

[Tuoder]

Deleting means that most people would be able to get at it. Single pass zeroing means that most people who know about undeleting would be able to get at it. On binary-level inspection it would appear new. Seven-pass would make it so that the CIA would not easily be able to get at the information, if at all.

Interestingly enough, a hammer would probably not do the job unless you actually broke up the platters.

[Simon]

The hammer won't do jack for you. Heating it above the Curie temperature OTOH would solve the issue for most practical purposes.

[ChasingApple]

A 7-pass would be fine if you plan on selling it to someone else, anything above that means you are trying to make sure not even our government can read your old data