Seriously, it's so hard to find a primer that does NOT contain silicones - I use a water-based foundation because my skin doesn't like them, which limits me to non-silicone based primers (basically, most of them). I sampled this in one of my first Birchboxes and was surprised at how well it worked - the first primer that did what it was supposed to in terms of increasing the wear-time of my foundation.
I have to moisturize well before using this, let it dry completely before applying the OC8. If I then give about 20mins for the OC8 to set completely, my foundation application goes much more smoothly (even application with no patchiness). Finally, it's important to completely remove your makeup and cleanse your face at the end of the day or else it could dry out your skin.
If most primers don't work for you, I highly recommend trying this out. It's the first one that actually worked for me and I plan to continue using it as my go-to foundation primer.