Would rosemary oil work on scars?

Probably.: While there are topical products specifically designed for use on scars to minimize them, there are no well-designed clinical studies to show that they are superior to some of the old-time products like cocoa butter or vitamin E oil. In my opinion, probably what is more important than what you rub on, is the pressure used to rub any moisturizing product on. Avoid things to which you are allergic.