The Bleaching Powder code D is suitable to be used in small quantities (less than 1 tablespoon for a full laundry) in washing machine with dark colours only if they are not delicate fabrics. It is recommended to use it with resistant colours, with the aim to prevent bad smells due to bacteria and moulds in the machine.
The Bleaching Powder (sodium percarbonate) is made by oxygen peroxide and sodium carbonate; after exhausting oxygen peroxide during washing, some traces of lime may remain, due to the combination between calcium or magnesium of water with Bleaching powder sodium carbonate.
It may also happen that the washing machine motion make the lime with some pills clump on fabrics, particularly synthetic fleece. How to remove it without washing again?
It’s enough to rub with hands the damp fabric, then run a sticky cleaner on the fleece.