I started noticing a weird film in my coffee cups when the coffee was poured from my thermos. Its been several years since I really gave it a good cleaning. I decided to clean w/ OxyClean. Oh my, what a disgusting mess. After an overnight soaking, the Oxy water looked like cola and the black flakes just kept comin- rinse after rinse. The "flakes" looked like black, soggy corn flakes. I had to OxyClean a second time as the flakes just kept comin. After the second soak (24 hrs this time), it just took a few rinsings and the inside is spotless.
I know many of you will come on a tell how spotless you keep your thermos, but I'm betting some of you will find the same disgusting mess that I did. Soooooo- hit your thermos w/ OxyClean and tell us how it went.