This "calblock" device claims to prevent limescale accumulation on water heaters in a washing machine. It sits between the water faucet and the washing machine; the water passes through it.
I cannot imagine how it could work. This video, made by a supplier, describes its function this way:
Thanks to 2 magnets, at a low temperature, molecules of calcium bicarbonate are splitted in aragonite, smaller molecules, that remains sospended, is not deposited and is discharged with the waste water
which is not satisfying at all.
How do the magnets convert calcium bicarbonate to aragonite? I cannot imagine how can a chemical transformation be caused by magnets. Also, why 2 magnets? How are they arranged?