I've never descaled my steriliser. My baby is 9 weeks old and I've had her electric steam steriliser since she was about 2-3 weeks old. I saw boots did a descaler that has now been discontinued so don't know what else to use. I use oust for my kettle but don't know if this is suitable. I don't know why it wouldn't be suitable but I know with the kettle I have to boil it a few times. There's other liquid and powder ones for the kettle, has anyone used any of these or do you have another method?