There aren't any real benefits unless you run programs super sensitive to latency (you would already know if you did) and it will cause the CPU to make more heat and use power for no reason.
For c-states OC with them off. Then you can try to turn them back on 50/50 shot whether you will have to turn them back off or not.
Personally learn to OC with adaptive voltage and all those good things. It lets the CPU idle at stock power usage and then ramp both power and frequency as needed.