I wouldn't reuse them, BUT when we bought our mugs at Pop in April the cashier specifically told us they were good for refills "for life." Her words, in responce to my husband's question ensuring they were good for the whole week we were there. There were many, many, many people using what were obviously very old mugs, from many different resorts and I never saw anyone stop them. I'm not saying it's right, but it would seem that most people here care more about it than Disney does.
I should totally start buying these refillables! Are they only good at resorts? Can you use them in the parks? What drinks can you get? Someone post a pic please. Ill buy in! If they are good for coffee I will totally get my 12 bucks worth
Then Ill have a travel mug instead of all these glass ones. 
If they only knew.... 




