Microbiologists rarely wash their jeans. The reason is because they know how to keep the color looking new without getting odors - they freeze their pants.
Freezing can even work in more extreme scenarios, like with waste water.
When waste water freezes, it is purified through the formation of a cleaner layer of ice. Then the clean layer of ice can be removed from the rest of the waste water, and the remaining waste water is more concentrated, which can be treated as needed with a lot less outside processing. Energy is required only for breaking the ice and transporting it from the waste water pool.
Credit: Lappeenranta University of Technology, LUT