I do time outs but there are times when I spank too. The most effective is telling them they are going to lose privileges.
when the kids won't follow instructions they go to time out until they are willing to follow the instruction. If they won't stay in the time out chair, they go to the time out closet. (this is allowed, per a child psychologist as long as the closet is at least 4'x4' isn't full of stuff the kids can hurt themselves with and has a light). Then they have to go back to the chair until they are willing to follow the instruction. Then they must follow the instruction.
we spank for bad words and physical aggression.
Losing privileges starts with this statement "you have a choice you can (do what ever I said to do) or you can lose your afternoon activity, mail (if there was any), tv privileges in the livingroom, freedom, tv in the bedroom, radio in the bedroom, toys in the bedroom, books in the bed room, decor in the bedroom, bedroom door.
I have to go all the way to the door about once a year so far.
My son is a very good listener, but he is sometimes stubborn. When this happens, I usually give time out or take away whatever toy/activity he is interested in at the time.. He only gets a spanking for something serious, like when he bit me on purpose after I told him that you don't bite.