Answering late, but nobody else did so I will: plain white 97-cent-a-gallon vinegar. Use literally the cheapest one you can find because it’ll be least likely to have anything else in it. The dish soap with the fewest ‘keep hands soft’ substances in it, also likely the cheapest. Plain castille soap will also work,…

I’m also in favor of beef tongue. Never had it, but it sounds intriguing.