
Originally Posted by
Kubla
It wasn't clear from what I found online-but I'm assuming that it's kitty litter soiled with urine that allegedly deters them?
Not that the other feline waste material is pleasant. With several dogs, a pet bird and a horse, I'm no stranger to poop-scooping. However, the litter box makes me gag and DBF-who wanted to keep this stray kitten 5 years ago-conveniently forgets to clean it. 
I believe the urine is the more important component, but in VA we just put all of the nastiness from the litterboxes down in the tunnels, since they were starting to tunnel under the indoor arena (NOT COOL!).
Good luck!
“Hope is the thing with feathers, that perches in the soul, and sings the tune without words, and never stops at all.”
- Emily Dickinson