While waiting for my dad to figure that out i was stopped by another shoe fixer. This guy wasn't nearly as nice as the first guy that glued my shoes. He wanted 20,000 dong for gluing them ($1) but my dad said 10,000 dong. So he agreed and while he was gluing them he said he could clean them too!
i believe the process uses some kind of acid. To protect your gums from deteriorating they put this gel over your gums where they meet your teeth to protect them. Once that dries with the help of some crazy blue light, they add a bunch of crazy chemicals to whiten the teeth.