FYI: Oxy Clean in sealed container... DON'T DO IT!

[MKLKT]

Sounds like when my sister thought dish soap would be a good alternative for the dishwasher... Foamed up and out and all over three rooms about 2' high.

[ScubaSteve]

I use similar chemicals in my research and I can tell your at those crystals are persistent as all hell. Try using a mild acid, like vinegar in water, to clean it up.