The spell sounds enough quirky to be able to let people know that it's just rubbish. You don't require any spells to be a witch. Anybody involved in witchcraft is termed as a witch. Being said so, if you are already involved in magickal arts, you are a witch! It simply means one who practises witchcraft.
That being said, any such spells that says about turning into a witch are rubbish. The spell neither will grant people powers and whatsover.