Be glad you don't know what a horrible task that is -- "cleaning the vats". Especially the one used for Filet-o-Fish all week. And the cleaning agent remains

Be glad you don't know what a horrible task that is -- "cleaning the vats". Especially the one used for Filet-o-Fish all week. And the cleaning agent remains in the oil for subsequent frying. (Or that was the practice 30 years ago, anyway.)