Ever since I watched a dog eat cigarette butts, I’ve questioned the idea that there’s anything that a dog won’t eat.
As Nisht points out, ROB’s information is erroneous. Yes, soap is made from lye and fat. Fat is not an emulsifier. Although lye is highly caustic and highly basic, soap isn’t. Soap tastes bad, as anyone who has accidentally got some in his mouth can testify, but there are many foods that taste bad. If you don’t believe me, google worst tasting foods.
Years ago, I was approached by a black man in Muslim garb, presumably a recent convert, in a supermarket. He wanted to know what I, as a Jew, do about soap. I explained that halacha doesn’t care about what we wash our bodies with, just what we eat. I don’t know if it’s normative Sharia to require non-pork soap for washing. Consult your local imam, I suppose.