It does a very good job.
The water in our area is hard, resulting in the need for one box every 4 months. The difference is evident in the heating speed and the power consumption of the washing machine, as it is faster and requires less power. This means that it definitely removes the salts from the heating element.

It is a very good descaler for my washing machine and dishwasher. It removed a large amount of salt and the result is evident.