When I was "in" (physically and mentally), I would show my displeasure by not saying Amen at the end. Kind of silly, but gave me a sense of revolt. :>
This was a regular occurrence at CAs/DAs, when long-winded gas bags would get up and blather for 5-10 minutes. I never understood that crap...worthless, arrogant prayers.
Of course, now I know they were just suck up douche bags to the DO/CO, so the whole thing makes sense...