Here is the right way to do it to really throw them off.
1. Assume an alias of some elder that you don't like from an old congregation. Preferably some out of state congregation that you used to attend.
2. Dress up and travel to another congregation where no one knows who you are.
3. Pop in last minute before the meeting starts, if there is any time for introductions, introduce yourself as Brother (alias) from (some other cong). Tell them that you had urgent buisness and had no time to make it back to your own congregation, or that you are out of town on buisness and will be leaving to catch a flight as soon as the meeting is over.
4. Partake.
5. Leave as soon as possible when the meeting is over, tell them you have urgent buisness or a flight to catch, make sure they know your name (alias) and what congregation you are from.
In and out, know one knows your reall idenditiy and some smuck elder will be getting a call about his partaking or at minimum, it will bring the numbers up.