Never heard of that, but I have past experience with opiates. Not doubting it, it is just another thing that I have yet to read about.
That said, you were talking about "kappa opiate receptor agonism", which, though it doesn't exclusively target this complex, more closely references the action of salvia than of heroin and morphine. The main idea stands.
To take another example, a lot of people think that various herbs feel like cannabis. The word for this is cannabamimetic. Many of them do not target the cannabinoid receptors at all.
Please just accept this truth. There's no need to make a big deal about it. I just wanted to respond so that people don't think in a reductive manner.