Can't speak for OCD, but I have ADHD and can relate to the incessant mental chatter and yes meditation did help. But it's also extremely difficult and I have never been able to maintain a habit. It comes and goes.

My suggestion is to try other mindful activities, for example I got really into whittling. It's a hands on activity and you have something to show afterwards, it's good to lock on your mind/focus.

Like someone else in the thread suggested crochet