That is the way to do it. Drop sensational inside office gossip on a co-worker and see if the story gets repeated. Just be sure that the gossip sounds like gossip, that it is extra sensational, and within the realm of possibility, then make sure it is only released to one target.
If the gossip surfaces within the organization, worse on the front page of the paper, the co-worker repeats tales.
Very difficult to work in an environment of sensitive information with staff sharing office gossip
Looks like the WH outed another leaker.
A very good point to ponder.