Is there a collector's rule about washing an original WWII carbine sling? Will this detract from value? I read somewhere awhile back here on the forum that you shouldn't wash your slings but I don't understand why. They certainly got washed in service. I have several that are kind of stiff and oily. They look pretty good but they feel pretty funky. They do have that 'been there ordinance smell' though - that I would miss. Any opinions or recommendations? Thanks.