iPod iPod secure erase?

[Deth]

Hi.
I've been using my ipod as a flashdrive to carry my stuff... work stuff and private stuff, but now i want to give it away or sale it.

now, my question is can i secure erase it via disk utility without damaging it? or it has to be erased with the non secure "restore" option of itunes?
Sorry if the question is stupid


Thanks!