He loved it, right up until we got a kitten. Both male, in case that's important, but after we got the younger one neither of them ever seems to react to catnip at all.
I've heard certain cleaning products can mimic cat pheromones (not sure how true that is, though), or at the very least affect the cats sense of smell which would affect a cat more than a human. My cat seems uninterested in cat nip.
Not all cats, but I did had more than one that liked a lot the smell of bleach (NOT sniffing from pure bleach but if you wash something with bleach and then wash your hands without soap it remains a little on your hands), my cats went mad, sniffing my hands, self-striking against them, etc.