You are looking for fleas in the straw.
Greek Proverb
You are looking for something impossible to find. Akin to A needle in a haystack.
No matter how much you wash a black person, you are wasting your soap.
Greek Proverb
This proverb is mainly used to express the futility of trying to change the mentality of a headstrong person ~ the color of a black person cannot be washed off~ and it does have racist connotations. In modern Greek, the word ___¹__ ~ arapis — black man~ is a lay ~ and at times borderline pejorative~ term — originally probably derived from the word ______ ~ Aravas — Arab~ .
At the deaf man’s door, knock as much as you like.
Greek Proverb
Some people ignore any advice or guidance that may be provided to them. In more modern Greek, there is a funny spoof of this proverb : ____ ______ ___ ¹____, _¹__ _¹’__ ¹_______ ~ When at a deaf man’s door, get in through the window~ .