Thank-you very much for your enquiry. I would love a bit more detail on what you mean by “facial oil”. You need to remember that some oils (particularly some essential oils) can cause pigmentation on your skin if exposed to the sun. Some can cause skin sensitivity. So I’m afraid unless you can tell me exactly what ingredients are in the facial oil you intend to use… I can’t really give you any helpful advice. We certainly do use products containing oils in them on oily and combination skins, but these are specifically formulated products and we use them for specific purposes.