I use mole grips but very small ones like needle nose pliers, the threaded stud is welded to a washer and the rubber is bonded to that, when it shears as you say they are a real pain to remove. If possible clamp the washer with the grips to the bracket it passes through, sometimes you can grip the outer edges with concave mole grips....its work picking some assorted size and shape ones at tool fairs....they can also clamp things in place to get you home!
