It is not dark arts if you are honest about what you are doing.

That's absolutely false. The terror management theory people, for example, discovered that mortality salience still kicks in even if you tell people that you're going to expose them to something in order to provoke their own feeling of mortality.

EDIT: The paper I wanted to cite is still paywalled, afaik, but the relevant references are mostly linked in this section of the Wikipedia article. The relevant study is the one where the threat was writing about one's feelings on death.