Don't wash that coffee mug!

Don't wash that coffee mug!  Funny article about an unlikely U.S. Navy tradition: never, ever washing out one's coffee mug.  I can attest to this tradition being alive and well at least through the '70s, when I was in the Navy.  Some of the saltier chiefs had coffee cups whose capacity was significantly reduced by the thickness of the tarry scum lining the inside of their cups.  And those old salts were very attached to those cups – if someone were to wash it out for them, I wouldn't give good odds for their survival...