Found this forum post to be very helpful and I think I may employ this more often when doing UpdatePanel related messaging-when-done…
You should call the method in this way:
All I know is that when I launched the script properly passing this.Page it worked properly. I had derived from Page to a custom base page, so maybe that had something to do with it.
Additionally, I refined it just a bit by building the script dynamically in a string and then passing that instead of just a literal in the static method call.
One more improvement I was considering is to embed this as a method on my aforementioned customized base page. Then i can just pass a name and the script to the method, and I won’t have to worry about the messy details every time.