back when I was a kid, my grandma taught me how to butcher, clean, and roast a duck... one of the things that sort of stuck out was that she showed me how to very carefully remove the preen gland, or "oil gland" as she called it, with a razor blade, as apposed to cutting it off with the tail... she told me that you save it because the oil from the gland is really good for waterproofing leather... she then threw it away, because we were only doing the one duck, and just one gland wouldn't amount to anything... but she did think it was important for me to know how to do... that is the only time I have ever heard of this practice... I have never found any reference to saving the preen gland for waterproofing in anything I have read, though it does make sense(probably like mink oil, I imagine)... has anyone else ever heard of this practice?...
