Yep they are shiny polished porcelain in an off white colour. I have tried so many different things it's not funny. I have a collection of steam mops but they leave too much water on the floor so I get water marks. After everything I tried I find metho and water to be the best but I have to use very little water so I have a spray mop. I have recently seen the Enjo fussy floor fibre mop so I'm going to give them a call on Monday and get someone out to test them.
What about vinegar? I use about a cup in half a bucket of hot water. Gets everything off and no steaks