I think I just figured it out. The instructions you all gave me are correct, but the songs I was trying this on did not start the chorus at bar 1, it was more like bar 5. They had a lead in before beginning the chorus. When I used bar 1 to mute the chorus with the F5 key, there is no chorus at bar 1 so it did nothing. When I changed it to bar 5 with the F5 key, I could mute or return to normal at will. My bad. I figured this was an easy issue, thanks to everyone who chipped in to help!