You definitely should. I do not have Carbon Copy Cloner--I use SuperDuper!--but I believe both make "bootable clones." I only used it because "Back in the Day," Time Machine did not make "bootable clones."
I did the same thing you want to do. I was on your system, I cloned it, I then tried El Capitan. I was then able to boot--again--from my clone and, if I wanted to--cloned to my El Capitan HD if I did not "wike it" for whatever reason.
Since you can boot from clones made by CCC now, you should have no problem doing that! Heck, there are Techies with Huge-Ass HDs that partition them so they can put a new OS on one partition to test it. They do not like it? They go to the other partition!
--J.D.