One of the main question I have gotten during my presentation for the World Bank Youth Innovation Challenge Pitch

was how do we clean the inner surface of the Anteneh Jerrycan from fungi because rural areas collect water from rivers and river water accumulate fungi easily. My first solution was manufacturing the Jerrycan in Design for Assembly (DFA) to disassemble when cleaning is needed on the hands of customers but this is a challenge to do in mass production on blow molding.  But now I figured it out. I am going to clean it using a magnet system. 

As seen in the above picture we install a very light metallic ring (red) that have outer diameter equal with inner diameter of the Anteneh jerrycan pipe (black). Between the two surface there can be a cleaning sponge like material to minimize the friction and act as a pipe surface cleaning material. By using a ring like magnet or half ring like magnet (depending on strength of the magnet and surface friction between the ring and pipe) we can pull the cleaning ring by moving the magnet which will clean the inner surface of the pipe as seen in the window cleaning system below.