We have tried 'no', quite sternly. He is 6 years old. He will listen if we catch him in the act.
We have hidden or put out of reach all stuffed animals, but would have bare couches if we hid all those pillows. We block him from those areas when we are not home, but he sneaks off and 'hits' them when we are busy doing other things (even if we just exercised him).