re: intelligent design for receptacles
Dummies may well reflect on the infinite choices made available in an infinite universe.
Dummies may also find that concrete (cement:sand:gravel) is a bad choice for rendering (due to the lumpy bits, or gravel) and that a cement render (cement:sharp sand) would be infinitely a better choice. Definitely a cement mortar (cement:fatty sand) would render an unsatisfactory result.
Given the infinite variables a cement render would be the choice of an Intelligent Designer.
