Sugar Soap is commonly used for cleaning surfaces in preparation for painting.
Sugar soap is a generic term and its makeup varies a little from country to country but generally it contains an alkali substance (sodium carbonate), an abrasive substance, an organic solvent, and water.
Sugar soap is a cleaning agent and can be effective for removing stains, grease, and loose paint flakes.
Sugar soap can also rejuvenate painted surfaces but you need to be very careful to avoid removing too much paint or damaging the surface.
It can be useful for removing odours and mould stains but will not kill the mould or the mould spores. Sugar soap will also not kill mould lurking behind walls, under floorboards or in ceiling cavities.
If you’re using it in its liquid form you’ll need to be very careful to avoid getting power outlets wet or letting it drip onto more delicate surfaces such as furniture and fabrics.
To sum up:
Sugar soap is a highly effective cleaner and is particularly useful for preparing surfaces for painting but it is not designed for killing mould.
Sugar Soap will not penetrate porous substances and kill mould at the roots nor will it kill airborne spores.
They will also identify and eliminate the source of your mould problem permanently.