OK, you've inspired me! I dug out the beef tongue thats been sitting at the bottom of the freezer for probably too long now, and let it thaw out over night. This morning I rinsed it off, and popped it into the slow cooker while I'm at work.
I'm very keen to see how it turns out. My husband looked a little concerned when I pulled it out of the freezer so he may require a little convincing tonight!