Interesting - never heard of this before, but your explanation makes it plausible.
Made me think of a joke:
2 drinking buddies talking about what happens after they die.
Says the one: when I am gone, could you do me a favor? Could you please visit my grave from time to time and pour a glass of wine on it?
Answers the other: Of course I will do that gladly, but I hope you don't mind if I filter it through my kidneys first!