Grab a hammer, an old pillow case for safety, and something your client can smash with the hammer. In my example I found a tile outlet that allowed me to take as many of the discarded tiles as I wanted without charge. Awesome! Make some phone calls, most likely you can find the same thing.
Place the object in the pillow case. Show your client how to safely use the hammer.
Ask you client to name their stress, triggers, or a situation that made them angry.
And let them smash away.
Because the smash material I used was tile, we then began painting the pieces of the tiles to be used as art or eventually a mosaic (separate post soon). If you are able to make something out of the smashed material, help your client make the connection of channeling stress or anger into something productive or positive.