Soak them in distilled water every time you take them out. If you do not have a container to soak them in, or if the retainer is dirty and you cannot clean it right away, you can soak it in a damp paper towel. Your retainer case needs to be cleaned regularly too. Clean it once a day before you put the retainer away.
Here's my answer he used many different internal tragedies in all the passages because he wanted to tell you about his life and how hard it was while he was a slave. I hope this helps.
