I see no issue using a refillable cup with a push button dispenser. The risk of germs spreading from the cup this way is extermely minimal. The germs are spread through pressing the button. The rule of not using a reusable cup dates back to the cup lever dispensers. All most every fast food place and self serve resturant uses them and people are expected to use the same cup. As a PP mentioned, it is encourged at the resorts. I use a refillable cup on the ship because of the environmental impact of all those paper cups and plastic straws being used. It makes me cringe. I wish
DCL provided every guest with a reusable cup to use.
Nothing replaces washing your hands with soap and water and the sanitizing towels Disney hands out before the dining rooms do not kill the norovirus. I wash my hands before every meal and don't feel the need to use a sanitizing towel less than a minute later. Washing is so much more effective.