Late last summer, we visited another local primary school with our Sputnik water jetting recycler (when it was brand new, never used - and clean!). Ian gave an introductory talk on drains and sewers, talking the children through what they can and can't flush down their toilet.
In addition he used two large bowls of water to show how easily toilet paper breaks up in water and how 'flushable' wipes do not break down. Finally, we had a fun game to demonstrate the suction of the recyler. The children rolled tennis balls across the lawn and watched how, even on the lowest power, the suction hose sucked up the balls! We had great feedback from the school, it was nice to do something in the local community.