> thus extra work for the buyer The soap water inlet can be a flexible tube that one can put inside the reservoir, then push a button and the exact amount of w

> thus extra work for the buyer The soap water inlet can be a flexible tube that one can put inside the reservoir, then push a button and the exact amount of water is added (or some more and have it overflow to the drum). > maybe requires some maintenance Not if done correctly. And if it wasn't done correctly it seems easy to fix. > so probably you also need to put some disinfectants in They can just come with a bleach tablet inside.