This is probably a really stupid question- I’m descaling my tommee tippee steriliser ready for babies arrival. So I have the Milton sterilising solution in there but do I just leave to sit in there or do I turn the steriliser on? I’ve googled and in the Tommee Tippee support page it just says to pour in 250ml of white vinegar or sterilising solution and leave for half an hour to 24 hours. So just leaving it in there will de-scale it? Or turn on the machine then leave it? Thanks in advance