My wife recently bought a liquid soap. Coincidentally, my eyes fell on the ingredients list. There are two items mentioned there that may create a problem. It contains glycerin, which is a derivative from animal fat, and yoghurt. My question to you is: is there an Issur of Bassar Bechalav behanaah?
Even though one is not allowed to benefit from meat cooked in milk, your liquid soap is OK. It is forbidden to derive benefit from meat and milk only when they were cooked together before they became inedible or spoiled and when they came from a species of animal that is kosher. Even then, it is likely they are a small percentage of the overall ingredients and are therefore “batel”.