Evolve Sani-Klo Cistern Block HolderDo you have number one's being left in the loo all day night? .. Or a tween teen that has forgotten how to flush? Our new cistern blocks are amazing at not allowing the pong to leave the bathroom for those unwelcome, and sometimes multiplied deposits. They are newly packaged by us, and waiting to be plopped straight into your cistern. Even better, which we highly recommend, use our Sani Klo device (i. e. plastic vessel) and simply insert into the