Why does a spray bottle work?
A few years ago, a British inventor appeared on a TV show called Dragon's Den (UK version of Shark Tank) and pitched his idea of an improved spray bottle called the Anyway Spray.Instead of a normal plastic tube inside a bottle with an opening at the end, he designed a tube with millions of tiny perforations along its length. This meant the spray bottle could operate at any angle (even upside down) and could empty all liquid in a bottle with no leftover.Here is a 1 min demo of the spray: 
https://vimeo.com/195318537Here's an explanation of how it works
https://www.youtube.com/watch?v=xXk46rvzdpYAnd here's the original pitch he made on Dragon's Den
https://www.youtube.com/watch?v=RjOvyjeZyIw