I wear slippers in my own house, and would take them with me if staying with someone, but not just for a visit/coffee.
I put my slippers on in the sitting room when I know I'm not going out again - more for comfort than anything, and change back into my shoes/boots when I'm going out, again in the sitting room. I would hate to be given someone else's slippers to wear, and well remember a party we went to years ago when people were asked to remove shoes. It was awful - apart from the stockinged feet and mutters of people who had come in their best shoes, there was a huge pile of shoes in the hallway, so people took ages to identify their own as they left, particularly the men, whose shoes were all very similar. Maybe if the invitation had said to bring your slippers it wouldn't have been so bad, but it came as a surprise to everyone, and I still remember it years later.