Hans Grohe Raindance E 150 AIR 3-jet 28518XX1 Installation Instructions / Warranty page 4

If scale deposits are noticed on the spray face, pour
about 3/" of a commercial scale remover, such as
Lime-Away™ or CLR™ ,into a shallow dish. Dilute the
remover according to the label instructions.
Soak only the spray face in the solution for the amount
of time specified on the label.
Rinse the handshower with clear water.
Reinstall the handshower. Turn on the water and al-
low the handshower to flush for at least one minute.