Oh yeah, you'll need root ofc., add 'sudo !!' and enter pass.

Joke aside: I misunderstood what was asked it appears. Re-reading the original post I'm still unsure what is asked.

But to be clear, you shouldn't use these commands if you wish to erase sensitive information, albeit if you use full disk encryption it will not really remove or add any value I suppose.

If you want to be sure you could overwrite the disk with random random bits or use a degausser which is properly the most complete/sure method of erasure.