As a longtime atheist, I've given invocations at public meetings, myself, on a few dozen occasions. A few times, I did so for government bodies, like city councils or county boards. Completely non-religious ones. Like that Satanist, my invocations always call for decisions to be made logically and with concern for those who aren't there to speak. However, I didn't invoke some other deity. I just ended with, "Thank you."
In some cases, I asked to give an invocation as a non-religious person, for reasons of fairness. In a few cases, I was asked to do so by someone in the group, who recognized that different forms of invocation should be part of the mix.
Oddly enough, my religion-free invocations were always well-received and did not lead to angry criticisms. Mostly, nobody noticed that I left off any mention of any sort of deity. I thought that was interesting at the time.
I have invocations (calls to fair and logical action), statements before meals, (recognition of sources), and benedictions (good words) ready to deliver on demand. I can deliver them at a moment's notice, and am always happy to do so. They are all brief and non-confrontational, and have no religious content whatsoever.
= new reply since forum marked as read