I hv the same problem. I allow my maid to use washing machine once a week (better hygiene as she's taking care of my baby), then hang some in the kitchen. Before she left for holiday, she has to hang them back into her wardrobe (no matter the clothes are wet or dry). Some will be dried by the drying machine. We hang our clothes in the toilet and she's not allowed to do so.
我工人D laundry 挂係她自己房。每星期六是她的laundry day. She uses washing machine because I dont want her spend so much time handwashing her clothes. She is quite hygenic so I don't need to ask her to wash an empty load. That would also upset her, I think. She washes her undies by hand every day and hang them in her room.
But when she washes baby clothes by machine, I ask her to wash an empty load first before doing my baby's laundry.