Great way to learn 3c is Korean 4 ball. Add a second red, hit both balls any way you want. Only foul is hitting opponents cue ball with yours. Teaches great control and helps learn the harder game of three cushion.
I enjoy it and I play it time to time, but I don't know how it helps you play 3c any better, it's basically straight rail but with the stipulation you detailed, and the opening break is a bit more difficult