I happened to switch on the radio in the small hours and heard this one on the World Service News: President Obama is planning to visit Cuba 'To cement the thaw' in the relationship between the two countries. Have you got any really absurd examples of mixed metaphors?
Not mixed metaphors, but I once worked with a manager who said, "Right team, shoulders to the wheel, ears to the ground, noses to the grindstone and heads below the parapet". I am pretty supple, but I couldn't manage all that at once.
I worked with lots of Polish people many years ago and at a colleague's retirement party one of them suggested we should drink to 'the new sweep'. (Which was me as I was talking on her job.) We didn't like to tell him it should have been 'broom'. He also said he had lived in the area 'monkey's years'.