Did you know that hamsters produce oils to keep themselves clean. They don’t need a bath with water this can damage the oils in their coat. Also there have been reports of hamsters getting wet and then shivering and sadly dying after their owners have made the mistake of making them wet in an attempt to clean them.
Please provide them with SAND not dust (dust can cause a respiratory infection). Children’s play sand is even recommended, it’s cheap, lasts long and is already treated. You can also get reptile sand that has no calcium in it.