The idiom - "wash your hands of something" means:

to have nothing to do with

The idiom "wash your hands of something" is an expression derived from the act of physically washing one's hands to remove dirt or impurities. In a figurative sense, it means that someone wishes to cleanse themselves of a situation, responsibility, or problem they no longer want to be associated with. The idiom implies a desire to disassociate from or completely abandon involvement in a particular matter.