The Bleaching Powder code D, so useful and versatile, is generally used for bleaching and hygienizing white and resistant laundry. Indeed it is possible to use it for dark fabrics too, on condition that they’re not delicate or esy-to-fade: the oxygen peroxide released by this salt may increasing dyes fading and create whiter stains. Instead there is no problem with resistant dyes and fabrics.
The Bleaching Powder (sodium percarbonate) is made with oxygen peroxide and sodium carbonate; when peroxide is exhausted, some lime traces may remain on clothes, due to the combination of calcium and magnesium (present in hard water) with sodium carbonate.
It may happen that the laundry machine motion make fabrics pills and lime traces lump together, particularly on synthetic fleece. How to remove them without washing it all again? It is enough to rub with your hands the damp fabric, then run a sticky picker.
On cotton fabrics, it is better to rub damp clothes with a dry sponge towel.