We have catnip parties at my house. I pull out the catnip and say OK, it's party time and start walking around sprinkling it on scratching posts, beds, etc. and all the cats get happy, happy. I only have 1 or 2 who don't care for it. The rest go bonkers!
I give my cat fresh catnip, because we live on a farm so there's always lots growing places, i tryed giving my kitty sum of the store bought stuff and he wouldn't touch it lol. i think it's perfectly fine for them lol and funny!