On the Undiscovered Future World tour I took about a month ago, they took us to the machine at the Imagination pavillion that cleans the glasses. Glasses from all 4 parks are taken there every day and go through a 5 stage machine that reaches 160 degrees to make sure that the glasses are sanitized. We were told that occasionally during peak season, there are 2 deliveries a day but usually there are enough glasses in one set to last the day. Hope this helps.