I have found the easiest way to pull out a recessive trait is by breeding the parent with the recessive with a 9T mid range trait...for example using a Black/White Russian or Bengal Snow with say a Bali Cream Lynx. Then keep breeding them until you get a boy and a girl box that are both hiding the recessive fur, I would then breed the son and daughter together and their box will show the recessive fur. Not with every single box, but with both siblings hiding the recessive fur it will show in some of their boxes. This is because its a double hidden trait so it will show fairly often, unless you have really stubborn kitties but it will show. I was taught to do it this way with very recessive traits and its a lot easier to bring them out in the boxes.
Thank you my Mentor for teaching me well