Why not jump on it?

Put the package into your shoe, heel, and jump?

Kids could do this for you with pleasure!

Let's hear from anyone who tries this!

That's funny!  I guess one could stomp on it and get some exercise in the process.  It would probably work about as well as beating with a hammer.

 Too funny!  Maybe I should try strapping it to the pedals on my stationary bike, that's a bit like stomping!

Seriously, though, I still am not sure if we have truly distinguished between "shock wave" effects and pure compression.  Though I must say Edie's post on the other thread argues anecdotally against pure compression.

$5 Cuisinart Food Processor from a Garage Sale + Kato = Happy Me.

Alternately, whack the crap out of it with Mona Kissel's Persuader.

I will try this next time I get a tough block of clay.  Thanks for the tip!

Sandra