The only reason you know your cat will seek out catnip is because you've given it to the cat. Because it's something that's active by scent, you don't have to feed it to your cat.
The idea that your cat is going to know if it's okay to eat something by instinct is ridiculous. Do you really believe that? I suppose all those cats (not to mention all the other pets) dying every year because they ate something they shouldn't have were actually suicidal?
I bet my dog had a bad case of motion sickness when she decided to eat some Datura, right? Or an infection when she ate a tube of neosporin? Maybe she was hooked on opioids when she decided to try eating my Suboxone, tired when she tried eating my Lunesta, and in pain when she tried eating my Tramadol?
Holy christ, I never realized how many times my dog tried eating my drugs before. Maybe she is suicidal?
Her instincts must be faulty, huh?
And Kava Kava is really, really easy to get in the US. Not in supermarkets, but you can get it out of Hawaii really easily. It's grown there heavily. If I wasn't allergic, I'd use it tons. As it is, I vomit blood and my BP spikes (160/110) and I ended up in the ER. Oddly enough, my bodily pH was also found to be too acidic for some reason.