Yes they can be cleaned in the machines. Please check the care label first for washing instructions.
These temperatures vary but as a guide are approximately Cold/Woollens/Delicate cycles – less than 15 °, Warm cycles – less than 40 °, Hot – less than 65 °
The temperature that is displayed on the washers is only an indication for the hot cycles. The Hot Water Heaters are set for at least 75’c so by the time the water gets to the machine it would be at least 60’c. The washers do not have heaters in them so the temperature is variable depending on distance from the hot water heaters and the room temperature.
Check Care Label First – Yes up to a cup of bleach could be used but only if the duvet filling is feather or down (not wool). Make sure the Wash Cycle is Warm Gentle to be safe or if you want to take some risk use Cycle Hot Wash.