I’ll try anything. They taste wonderful, but I don’t have the patience to deal with them, nor the strength - even tried a vise clamp.
My brother just sent me a cracker that has very sharp razor blade type blades in a pliers-like tool. It works very well and am anxious to try it on hickory nuts.
Put them in plastic ziplock bag , that is in a burlap sack, on a concrete surface roadway , or driveway.
Then drive the car tires over the baggie and sack.
Easy ..peasey ! Then separate the meat from the shells from within the plastic bag.