Yeah, I did those things and around the foundation of our carpeted basement after a disastrous experience with a plugged downspout in a Seattle monsoon.
I sent up alarms and text messages in both Elk and CQC, and have this insight to pass along.
I set them up on separate zones to text me when they got wet (violated) or dried (secure), and we were overseas when the only other water event I have experienced (another monsoon) occurred. A couple of hours (I think) following the initial alert from one zone, I was getting texts (and emails) every minute (or less), with dozens and dozens and dozens of texts over the next hour or so.
This would all have been fine and dandy if I had been in the US with an unlimited text messaging plan, but these things were coming in at fifty cents a pop so I finally called VZ and had them shut off text messages (a real trick to do from overseas). I surmise that as the sensor (most likely the water moccasin) dried, it never dried completely at once, so the moisture level somewhere along its length was high enough to re-trigger the sensor. I could imagine the same thing might happen to the under carpet triggers too.
In any event, when I got home I revised my rules so that after an initial water alert from any zone, there is a swinger delay of x minutes on both the wet and dry triggers. I also have a rule that checks every hour to see if any water zone is violated, and if so, I get a text that tells me which ones are still wet so I have an idea of what's going on.