I use a similar product (giovanni's version) every now and again, and I've been modified CG for over a year. My advice is to make sure that your hair is well-moisturized before using the product. Silicones aren't necessarily bad for your hair in and of themselves. However, they form a barrier that prevents moisture from coming in or leaving the hair (which is why it helps with frizz). They also require a sulfate shampoo to get out. Most of the time, you can get away with using a low-sulfate shampoo (burt's bees, giovanni, alba, and loreal are some widely available brands that make sulfate-free shampoo).

Go ahead and look up your hair type to figure out some good ways to moisturize. I use a little bit of coconut oil on the bottom half of my hair. You can use conditioners with oils in them if you're not sure about using straight-up oil. Just make sure you moisturize your hair before you use the product!