I bought this bag of catnip for about $2,so it's not at all expensive. And yes this is sold for cats, but catnip isn't harmful in any way to pets and humans.
I am using this for my rabbits house. This is behind his cage and as you can see in the picture above,the roaches are basically invading his home,which is really gross.
What you want to do is just take a handful of the catnip and disperse it where you know roaches visit.
Roaches hate the smell of catnip so it repels them,but dont forget to keep adding the catnip every once in a while. Don't forget to check out my other guides!