your doing it all wrong......take a old sock one with a hole in the heel. take the cat nip and crumble it up. now take the sock and cut off the end part leave it like 4 inches long, dump cat nip in your new bag. and use a small zip tie to hold it closed. toss to kitty, and wait for the live entertainment to start.
what they do is lick, chew, suck, rub it all over.( the pouch will be real wet) and theres no mess to clean up. when they seem like they have had enough, take it away and save it for another day.