That's a great question! A heavily used outdoor trash can can get pretty nasty, but with a good routine, it's totally manageable. Here’s my tried-and-true method.
First, safety always. Put on sturdy rubber gloves, old clothes, and consider safety glasses, especially if you're using strong cleaners or a pressure washer.
Pick a sunny, breezy day and take the bin to a grassy area or driveway. Empty it completely, scraping out any stuck-on debris. Give it a good preliminary rinse with a garden hose to loosen things up.
Now for the deep clean. Mix a solution of hot water and a heavy-duty degreasing dish soap or a dedicated all-purpose cleaner. For a natural option, a cup of baking soda with a quarter cup of castile soap works wonders. Scrub every surface, inside and out, with a long-handled brush with stiff bristles. Pay special attention to the bottom and under the lid.
For disinfecting and killing odors, you have choices. A vinegar solution (one part white vinegar to one part water) is excellent for disinfecting and cutting grease. Spray it inside, let it sit for 10-15 minutes, then scrub and rinse. For serious sanitizing, especially after raw waste, use a diluted bleach solution (¾ cup of household bleach per gallon of water). Let it sit for a few minutes, then rinse *very* thoroughly.
If you have access to one, a pressure washer on a low-to-medium setting is fantastic for blasting away grime and old stains. Just keep a safe distance to avoid damaging the plastic.
The final, crucial step is to let it dry completely in the sun before putting in a new bag. Sunlight is a natural disinfectant and helps eliminate lingering smells. For ongoing freshness, sprinkle a bit of baking soda in the bottom of the clean, dry can before each new bag.
Aim to do this deep clean every 3-4 months, or more often if you dispose of a lot of food waste. Your nose (and your neighbors) will thank you!