I'm looking for a "quiet" clicker, but there don't appear to be any in my area. For potty training, it's a moot point, since Thor knows where to go and knows he gets a treat for going there. If I don't see him go, he'll come running to get his treat.
As for the 1% that's left - if I saw a pattern, I'd be addressing it.
This off-pad pooping just started.
If you care to read back to the first page of the thread (it's a long read), you'll see that Thor is several years old, and came to me untrained. I thought I had him completely trained in my apartment and just needed to solidify the lesson not to mark in my office. I have no idea why he's decided to be devil-may-care with his poop both at home AND the office now.