No, Selleys Original Sugar Soap will not be the best solution to remove built up calcium and lime scale.
We recommend using products in your Hillmark range. Hillmark Scalex Heavy Duty Home Descaler rapidly cleans scale from plastic & metal parts. It easily removes tarnish & mineral deposits from stainless steel shower heads
A warm solution of this will help to eat away the built up scale. Try using it with one of our Selleys 'Wash Up Wiz' scouring cloths for the best effect.