I don't think jojoba oil gets in there at all. I don't think it's one of the oils that is absorbed into hair. I could be wrong though..I'm still learning which ones do what.
As for the coconut oil, I think it depends on how much silicone you're using as well as how often you're clarifying. If you're using cones every day, then your hair probably is not getting the nutrients from the coconut oil.
But if you just use shampoo and conditioner with cones in them and clarify your hair periodically, I think you should be okay. Stuff can still get past the barrier that it forms, you just have to be careful not to let the silicone build up to the point where they choke your hair.
And even that point is different for everybody, due to differences in hair density, thickness, texture, condition of the hair, etc.. You just really have to listen to your hair and let it tell you when.
I believe that when your hair is coated, you'll know...it's just a feeling. When my hair is coated, she feels greasy and slick, but still dry dry dry. I don't know how it feels for your hair, but I'm sure you do. As long as your hair isn't getting that feeling often, and is happy with what you're doing, (and your hair sure looks happy to me
) then I don't think you need to be worried.
Oh yeah...and I don't know if you're moisturizing or not. In my opinion, coconut oil is more of a sealant than a moisturizer, even if it is partially absorbed. But once again, I could be wrong...stillll learnninngg...
I hope that was helpful.