I bought something like that not too long ago for Rascal. He loves it - and it is dribbling - icky mess after he is through with it. But, I don't have catnip all over the place. He loves this one so much that he "hides" it.

I have cardboard scratching boxes and the mess from the cardboard is usually more trouble than the catnip to clean up.
Awful to walk on in your bare feet!