Waterwise Kleenwise Descaler - water mineral remover

Waterwise Keenwise Descaler -:
I have used this product and I bought my original container at the time I purchased my Waterwise distiller. Frankly I paid less for it then Amazon charges. In any event, it seems to work fine, although it's still not real clear to me how to get the scale off the inside of the lid, when the instructions warn against filling the boiler pot over the "max" line. The water obviously splatters up there, so that tends to make cleaning the lid difficult. Oh well.