Cleaning the Outside of a Thermal Coffee Pot?

My request is about a thermal coffee pot that I no longer use for coffee but would like to get it cleaned up for taking to the park when the children and doing there sports. The cover is coffee stained and I believe I was successful in getting the smell out but would like to get the stains off. Since it is thermal I am afraid I will ruin the part that keeps the contents either cold or hot whatever it is being used for.