does full ad/ crit kog work ?

It works, but it's not as strong. You see, your W only deals half damage, and a little %hp damage.

So if you build crit, you'll still half half dmg, making it just like any other champion. BUT it does proc on hit effect 2x as much. Making a build like:

insanely strong. I believe even the armor pen build works,it probaly won't be as strong but.

Since it's double the armor shred. But I don't know why its not played.