When you wash your hands of something, you choose not to take responsibility for it any more.
The studio executives turned the movie from a drama into a comedy. The director got angry and washed his hands of the whole project.
Mr Brooks was tired of helping lazy students every day. He decided to wash his hands of them and only concentrate on the pupils who worked hard.
If you say something will not wash with somebody it means that it won't be accepted or believed by that person. The phrase is used informally.
Susan said she was late because she had to go to a funeral, but that excuse won't wash with her teacher any more. He now knows there was no funeral.
Hungarian doctor Ignaz Semmelweis discovered the importance of handwashing in stopping infection in 1847. He realised doctors were transferring infections to new mothers because they didn't wash their hands. After he introduced handwashing rules, deaths were significantly reduced.