I do largely believe in this when it is very straightforward a situation.
E.G. If someone was criticisng my house being messy, when theirs was also a mess, or my dress sense, if they had a similar one, a bit like the Aesop's fable is it? About the Crab that could only walk sideways?
But then I think, you don't need fully clean hands to have a point. If someone criticised my driving, when they couldn't drive themselves-it doesn't mean they can't recognise a bad driver.
Same as I know a crap doctor when I encounter one, even though I am not a medic. Or a crap waiter, even though I am not one.
What are your thoughts on it?