I just put them in freezer bags and when I have time I can them. Usually in the late fall sometime. Sometimes I would core them, but not always. I like your idea of putting them into warm water... I could start on the tomatoes without having to wait for them to thaw enough to take off the peels.

I discovered that trick by accident. I wanted a thawed tomato immediately, and thought I'd hold one under warm running water to defrost. The whole skin just slipped off in my hand! It was a lightbulb moment! LOL

I wouldn't suggest it, however, if you halve the tomatoes, as in the picture that was attached to my tip. That could get messy.