When you do your last sulfate wash, I would strongly recommend a clarifying shampoo with the ingredient "sodium lauryl sulfate", which is the harshest sulfate out there. I just came back from the shower washing my hair with a clarifying shampoo that has the harsh ingredient I just mentioned, and so I'm quite confident that any silicones that was in my hair is pretty much gone and dead.
After that last wash, go ahead and apply the CG friendly conditioner. There are so many ingridients out there, you're right... so I'll make this simple once more: Anything that ends in -cones, -xanes, -colons, -fates or -phates should NEVER touch your hair once you go CG. Ever. No ifs, ands, or buts. I thought my hair was doing good until I realize that my "flyaway frizz" problem that I kept having was from that DAMN Garnier conditioner that I thought was CG friendly but it looks like it's suddenly not anymore.
Be careful, I say!
The Curly Girl book by Lorraine Massey stresses on only buying two essential items: A conditioner and styling gel. That's another thing... Your hair gel should NOT have silicones (again), and it should also be alcohol free, and have little-to-no fragrance. A clear tinted gel is preferred. An ideal gel should have these two ingredients (I have used a CG friendly gel before without these ingredients and had no issues, but just in case): PVP (polyvinylpyrrolidone) and PVP/VA (vinyl acrylate)
You do not have to waste a lot of money to buy CG friendly products. You can find them in your local drugstore without blowing a hole in your wallet. That's what I'm trying to do and so far my hair and wallet are cheerful.