I am trying to make some cat toys with Valerian root in them >

and from my own observations at home with my own cats it seems that it's affect on the behavior of the cats is time limited

. As though the valerian root loses its "stinky" and the cats stop flipping out over it after a few hours. Even if I put the Valerian filled toy up for a day or two and then bring it back out for them they are not affected by it hardly at all. But if I sprinkle some more onto the toy then the insanity,

the playing, starts up again... Only to die out again a few hours later, seemingly forever.
What is the deal with this? And how can I extend the activeness of the herb longer?
Also:
Since I am trying to bring them to farmers market and to my friends on Facebook and to give to the cats & dogs who languish in pent up isolation and boredom in cages at animal control or even at veterinary offices how would you suggest I package the toys & herb? Already within the toy? Or separately in a little package to sprinkle on or into the toy? And would the dried chopped up plant work better than the powder? (which is what I have used so far only).
I am open to any and all suggestions... Thank you...