make a clean sweep

1.  Remove or eliminate unwanted persons or things, as in The new owners made a clean sweep of the place, intending to replace all the equipment. This phrase replaced the much older (16th-century) general sweep. [Mid-1800s]
2.  Win overwhelmingly, as in Our candidate made a clean sweep of all the districts. This usage is most often found with reference to success in a sports competition or election.