But your command line examples show, at different times, an equal sign, no equal sign, "--OC1", "--OC 1", "--oc1". Sorry, there is confusion.
I second that. It's a HUGE confusion. I see author's train of thought there, but it's overconsistent.
"--OC 1 1 1 1 1 1 1 1 1 1 1 1" worked fine for 12x 1080ti gpu rig, Gminer 1.61.
Seems to give total of ~40 Sol/s extra for whole rig, up to 690 Sol/s, compared to without OC1.