I just bought some this week (from Lidl, very cheap, very nice) and cannot believe how effective they are.
We misguidedly put white paint above the dado rail up the stairs and it's always grimy, cleaning it with detergents is messy and not even particularly effective, the microfibre gets it all off with hardly any effort and no mess! I've been flying around the house like a TV commercial rubbing dirty bits and going "look! look!" to my children (who are unenthralled )
If you haven't tried them yet get some!