If you really want to reduce the arms as ORS and other verbal tics, you're going to have to do something that seems contradictory. I need you to stop focusing on not saying arms. I need you to focus on actually communicating ideas of interest to the person or people you're speaking to. Think of it this way, I'm not a golfer, but my golfing friends tell me, if you go out on the golf course and you just focus on not hitting in the sand trap, you're much more likely to hit the sand trap, than if you focus on hitting the ball into the hole. It's exactly the same way when it comes to public speaking, giving presentations, talking to people in uncomfortable situations, or even leaving voicemails, you need to focus on helping the person you're speaking to focus on giving them ideas that are interesting and useful.
Don't focus Oh hope I don't say I hope I don't say him but I'll focus on the ideas for your audience.