Demonstration of results from softening hard rubber with mixture of wintergreen oil and isopropyl alcohol.
Caution, don't breathe the fumes and wear gloves and eye protection while using wintergreen oil. I used 3 parts alcohol to 1 part wintergreen oil. Some folks use 5:1. Let it soak for at least 24 hours, sometimes it takes days depending on how hard the rubber was. The rubber parts will temporarily expand but will shrink back in time.
