Steve,
Sorry I didn't see this post earlier.
I am serious. Yes it works. I have a PC reading a USB load cell that weighs the PVC septic pipe in my house. Based on the weight I can detect if it is backing up. I then tell the CM15a unit to shut off the water (I have a WaterCop installed), washer, water softener and furnace. I also email myself and text my phone.
It works great. It has detected a problem and correctly shut off appliances about 6 times now. In fact, just today we finally found the actual source of the septic issue and replaced the offending pipe (partially blocked, but hard to find) so I don't think I'll NEED the system any more, but it sure served it's purpose.
I can email you an article I wrote with pictures if you are interested.