In a way, your situation sounds simpler. I have ‘stolen’ from people I interact with before. I always let them know beforehand when I do. So far the reactions have always been positive. And often people feel flattered they inspired me. But I can imagine a piece of creative writing is a little different than a product.
Sounds to me you need to do some experimenting anyway. If this is about scents, what you plan to add might go better with different oils and you won’t really know until you try.