I did clamp the tool down with the quick release, very snugly.
But when I used my crescent wrench to turn it, since the freewheel was a little gnarled, it just made the park tool sort of shift and "derail" out of the path of the little grooves its supposed to stay in & turn.

The park tool is in great shape still, it just keeps chewing up the grooves of my freewheel, and soon there will be nothing left except a flat flush metal surface.

I think i'm going to have to dissect it with a dremmel cutting wheel, sadly.