I mean, I do understand how they work, and I do understand hand washing procedures. I dont think Disney should rely on guests to wipe down their cups to refill them though, and I don't trust fellow guests to take the time to do that. It is hard enough to convince folks to follow more important rules on sanitation. If there's a CM there helping guests use it, I think that makes total sense, but otherwise I'd have a hard time believing most people would actually fully sanitize their cup before setting it down. Especially as cups are something that comes in direct contact with your mouth. Most restaurants that are open and typically allow guests to self serve beverages no longer do that, and will have an employee get the drink for you, because of this very issue.