This is the pic of Hayden and Clyde that I refer to as "Grrrrounded"
My cat, Clyde, knows quite a few words including a few commands... he just chooses when to listen. We have certain areas of the house that are off limits for the cat and dog, which they clearly know... though bravely sneak into from time to time. When the cat is missing for too long, we ask Hayden, "Where's the cat, where's Clyde?" Inspector Hayden starts sniffing out the cat and eventually solves the case... just like Scooby.
Recently Clyde has been getting braver and trying to rule the house. He's been getting into all kinds of dangerous stuff, so to counter this aggressive power-shift... I gave our dog, Hayden, some more authority. Now if I tell the cat to do something (or more likely to quit doing something) and he hisses back, then Hayden is allowed to go over and growl and/or bark if necessary (kind of like a warning shot) to let the cat knows he's outnumbered. So far it's working.
The punishment... Clyde has to spend some quality time laying next to the dog. Hayden especially likes it when the cat gets in trouble and has to lay next to him. Hayden's dog bed becomes the "time out" pad (or what I like to call pet prison). Then, Hayden goes into full enforcer mode - this is when I start calling Hayden by his new name... The Warden. Clyde has to stay on the bed next to Hayden until he can be good without talking back or hissing. If he tries to escape, Hayden comes to me and tattles on Clyde. Hayden loves it... the cat, not so much.
So far the cat is getting to the point where he can be trusted to not get into stuff even if the opportunity is placed before him (food in open site, closet doors left wide open). On a side note, the only negative outcome I foresee so far is that Hayden is enjoying this way too much. Hayden's abuse of power could be on the horizon, but for now this system works well.