Does dishwashing soap need to be kosher? 🧼🍽️

Hey, Rabbi Gersten, why does dishwashing detergent  have a hechsher? Well, strictly speaking,   dishwashing soap does not require a hashgacha  because it's not edible. On the other hand,   though, there's an old custom to have  kosher soap. This already dates back to   the time of Rabbi Yitzchak Elchanan Spektor,  the Kovno Rav, he gave the hasgacha to the   Rokeach Soap Company, and this is back in the  1800s already. And there was always a hiddur,   a stringency to use kosher soap with your  dishes. Sometimes, some soap remains on the dish,   and that could end up in your food. People  didn't want to have any animal products even   though they are not edible. But there  was this extra stringency of having a   completely kosher kitchen. Nothing non-kosher  on your hands, in your food. And therefore,   if a person is, you know, at their sink and  there isn't kosher soap, they could use it.   But if a person's in the supermarket and they  have a choice, might as well buy the kosher soap.