I’d treat this like a small outdoor cleaning job rather than a quick scrub. Years of built-up grime usually means layers of grease, food residue, stickers, dirt, and odor, so the key is to work in stages and use the right products long enough to break things down.
Start with safety and setup. Wear heavy gloves, eye protection, boots, and a mask if you’re using strong cleaners or pressure washing. If these are public urban trash cans, check with the local authority first and follow any rules about washing, wastewater containment, and disposal. Never let cleaning runoff flow into a storm drain. Use absorbent pads or a containment mat, and collect the dirty water if required.
First, empty the can completely and bag the trash. Scrape out loose debris with a shovel or stiff scraper. For compacted grime, let a degreaser soak first rather than trying to chip it off dry. Apply a heavy-duty degreaser or alkaline cleaner to the inside walls, base, lid, and any handles. Give it the full dwell time on the label—usually several minutes—then scrub with a stiff brush. A brush with a long handle saves your back.
For really stubborn buildup, repeat the degreasing step. Then pressure wash if you have access to one, starting from the top and working down. Keep the nozzle moving and don’t blast too close to plastic, painted metal, or seams, or you can damage the surface. A wet/dry vacuum helps remove standing dirty water. If pressure washing isn’t allowed or available, use a hose with a good nozzle and plenty of scrubbing.
After the grime is gone, disinfect the can with a suitable disinfectant, following the label directions. Pay attention to the lid, rims, handles, and the bottom corners where residue collects. Rinse if the product requires it, then let the can dry completely in the sun with the lid open if possible. Dryness matters because moisture feeds odor.
For odor, don’t just cover it with fragrance. Clean and dry first, then use an odor neutralizer or a light dusting of baking soda if appropriate. For ongoing control, line the can if local practice allows, empty it more often, and schedule regular washouts. A quick rinse and degrease every few weeks prevents the job from turning into a major restoration project again.