Cones are are found in a lot of commercial hair brands. They basically coat and smooth the strand. Some folks prefer to stay away from them because they don't allow moisture to penetrate the strand, so the cones are acting as a barrier. Personally I like cones, and like most things moderation is key. I only ever use silicones on wash day. I tend to use natural based hair moisturisers and oils to seal and I don't have problems in retaining moisture.
Thanks! And I totally feel you on that Houston humidity, Solitude! So, would it make sense to moisturize your hair first, then seal with a product that has cones? I hope that makes sense...