That's an excellent question that gets to the heart of urban maintenance! While hosing down a trash can seems like the quickest solution, the reality of proper cleaning is a bit more involved for both effectiveness and public health.
Simply spraying the interior with a garden hose might remove surface debris, but it's largely ineffective against the sticky, caked-on grime and, more importantly, the bacteria and germs that thrive in these environments. This method can actually spread contaminants through aerosolized water droplets rather than eliminating them.
For a truly clean public bin, here's what municipal workers and professional cleaners typically do:
First, the bin is emptied completely. Any remaining debris is scraped out. Then, a dedicated cleaning solution or disinfectant is applied to break down organic matter and kill germs. High-pressure washing is often used, but with the key addition of cleaning agents. After scrubbing and rinsing, the bin must air dry completely before new liners are installed, as moisture encourages bacterial growth.
For your home trash cans, you can adapt this process using hot, soapy water or a vinegar solution, a good scrub brush, and thorough drying. So while your instinct to hose it down is on the right track, adding proper cleaning agents and mechanical scrubbing is what makes the difference between a visually clean bin and a truly sanitized one.