Momster that's awesome.... are you also leaving the plug in as well as the condom with a hole in it? I did that all of today and I got zero splashback, I also intentionally filled all the cartos I tested this on far and above full. Now I am testing it with the condom pushed all the way down and the plug removed. If this works, then assuming I can find a way to enlarge the hole in the plug it should work without the need for the condom. The larger hole in the plug not creating enough suction to pull in any condensation that forms on the bottom. Well in theory anyway.
T