Quote Originally Posted by CoffeeCup View Post
"To completely eat up a pood (~16 kg) of salt." when used as a stand alone phrase it means "to became very experienced in something".
I disagree, this expression indicates a closeness in relationships between two people (я с ним пуд соли съел) means that the two lived through much and know each other perfectly while when you become experienced in something you say "я на этом собаку съел" (I ate a dog at this). But no, old Russians didn't eat dogs, and I don't know why we say that. Nobody knows, actually.