Two weeks ago we implemented the "Homeschool Detention Program" and it's working wonderfully! The girls and I made a list of rules: no laying down during class, no yelling during class, no playing with the dogs, etc. and posted them on our cork board. Every infraction equals 5 minutes of detention. Detention equals helping me clean on the weekend with absolutely NO grouching.
My house is much cleaner and older dd has a nicer attitude too, believe it or not! :)