I've got one on hire and it's brilliant, but I was wondering if anyone has put the bottles and funnel thingys in a microwave steam steriliser? On the instructions there's a picture of a microwave with a line through it, so I assumed it meant don't steam sterilise in the microwave, but I'm wondering why. It's such a faff to have to boil them every day. The bottles are medela ones, but they aren't the rigid ones like the avent ones, the plastic is a bit thinner, so I was wondering if that's the reason why. Will the microwave melt them? Has anyone tried to microwave them?