I found the same about oils. I think it has something to do with malfunctioning sebum glands due to a toxicity in the body, my bet is a heavy metal or toxin. If you add oils yourself on the outside like you have been doing then no doubt it will keep your SD less noticeable. I could and would also recommend flax/fish/chlorella or spirulina as an "internal" method of oiling the problem areas, I find internal omega-3 helps quite a lot! I would advise against supplements from Japan or China though, radiation and all. I get most of my supplements that i used to get from china or japan from india. Its about the same quality and free from radiation to the best of my knowledge.
I would keep going with the oils on your face and scalp like you have been doing and try to add some internal oils into the mix. If you really wanna blast the SD then look into EFT as well, you can use it to reprogram your sebum glands to be more officiant and thus in the long term "Fix" your problem.
I'm not really sure why i wrote this message, I am generally kinda quiet but hey! I guess there is a reason for everything.