I use them as well. My husband about flipped when he saw me melting mp soap in the pyrex and then later use it to measure stuff for dinner. I looked at him and said, what is wrong. He is like, omg you used that to melt soap in and now you are using it for food. I say, what is the big deal, I washed it. And he goes yeah but you melted soap in it and I go, well, what do I wash the dishes with? He just looked at me and walked away LOL! Dish soap has fragrance in it as well so I am not at all worried about melting mp with fragrance in a pyrex cup and then using it later for food. After all, when you wash your dishes by hand or even in the dishwasher, you are washing them with soap that is full of fragrance oils too Now, anything I use with the lye on cp soap I certainly keep seperate. MP soap with fragrance is no different than dish soap with fragrance IMO. Angi