Spitting feathers means angry in the Black Country/Staffordshire. And he`s/she is in her oil tot. Which means they are doing something they really enjoy and are in their element. I love daft sayings and the meaning behind them.
Well, there you go - I had never heard of spitting feathers meaning being thirsty and had always thought it meant being furious! You have described it well, FarNorth. My father used "spitting tacks" for being furious, and I rather like that one.
There's one which has come up on MN before, and possibly here too. As I know it, it goes "If she thinks that, she's got another think coming", but there are those who would say that "she has another thing coming", which doesn't make sense to me.
A friend's mum used to refer to a milestone round her neck . We were at a function when someone was retiring and the speaker said that this chap always had his finger on the ball .