Yeah I've just used a hammer to crack them open. They are a pain in the ass tho, if you're not careful the meat will get pulverized lol. I never tried a heavy duty nut cracker, but this is only my second year doing it!
I knew about the natural weed killer it contains, so I throw everything out into the garbage for now. Thanks for the tip tho. We get free woodchips for mulch when we need it from tree service people.