What does "mutual hand-washing" mean?

[cherin]

Hi, I am studying English. I came across the phrase "mutual hand-washing" and could not find the definition in any dictionary.
I appreciate if you kindly advise me of what the phrase means.

The phrase is used as follows:

In most seats of power, a local town hall or a national capitol, it doesn’t take long for decay, depravity, toadyism, mutual hand washing, ass-kissing and favoritism to leave their lethal little droppings.
(BoniLogue » Time For a Flushing)

[Ouisch]

"Mutual hand washing" is similar to "I'll scratch your back, and you scratch mine." I'll do a certain favor for you, if you do this other favor for me. In politics, an example of mutual hand washing is the mayor of a city will give the owner of a large manufacturing company tax breaks and will bend the rules as far as pollution or parking or zoning, as long as the manufacturing company owner promises to give the mayor's brother-in-law a well-paying job at his factory (even though the brother-in-law is not qualified and has no skills).

[cherin]

Thank you, Ouisch!
I could not find such meanings that you suggested. It cleared away my question. I wonder why no dictionary provides them.
I appreciate this site as well as you very much.