Believe it or not, despite the manual labour required, hand-washing your bras can be more time-efficient than using a washing machine.
Just fill a sink with cool water. Drop in some hand-wash liquid lingerie detergent or any other mild detergent. Pop in your dirty bras (ideally with the clasps fastened so they can’t snag anywhere they shouldn’t) and give them a little swirl around in the water. Soak for 10 minutes, then gently rub them all over, concentrating on the underarms and back band.
Rinse in cool, clean water, then give a gentle squeeze to remove some of the water (but no twisting or wringing as this can damage the elastic).
Lay the bra on a clean, dry towel and roll it up to soak up even more excess moisture. Then reshape the bra ready for drying.