A weak mind is fertile ground in which to plant a rumor.
Indeed, if your idea is strong enough, it can take the place of established information in the thoughts of the feeble-brained.
Simply state your rumor clearly, be sure it’s in-keeping with what your idiot listener wants, and watch his or her imagination fill in any details your fanciful story might lack.
In this way, fools are better controlled by lies than they ever could be through the truth.
They want to believe, so they do, and they give it no more thought than that.
Or so I’ve heard…