Contact Brownell's Gunsmithing Supply. Read the mentioned articles by Dr. Gaddy. Not to be pedantic, but CCH is a lot more complex and difficult than bluing/blacking or browning. It can be learned, but you are very unlikely to be able to simply replicate some textbook process. You will need to develop your own process due to variations in temperatures, times, and materials. Unfortunately, there is a big up-front investment to even start experimenting.