Honestly, the best method depends on what the can is made of and whether it’s painted or powder-coated. I’ve cleaned a few neighborhood cans, and rushing it usually makes a bigger mess. First, get permission if it’s city property. Then put on nitrile gloves, eye protection, and a mask if you’re using solvents. Work outside or in a ventilated area, and lay down cardboard or a tarp to catch runoff—don’t let cleaner run into storm drains.
Start with the gentlest thing that might work: hot soapy water, a stiff nylon brush, and a microfiber cloth. Sometimes fresh spray paint or marker comes off with a citrus-based graffiti remover or a little denatured alcohol. Test on a hidden spot first, especially on plastic, because acetone and strong solvents can melt or haze it.
For metal cans, especially unpainted or powder-coated ones, a gel or aerosol graffiti remover works well. Apply it, let it sit for the time on the label, then scrub with a plastic scraper or brush. For stubborn paint, a pressure washer on a low-to-medium setting can help, but keep the nozzle moving and don’t blast seams, decals, or painted logos. On plastic cans, use a citrus cleaner, hot water, and a non-scratch pad; a magic eraser can help with light scuffs. Avoid wire brushes on plastic.
If it’s a big tag, sometimes the fastest fix is to paint over it with color-matched spray paint made for outdoor metal or plastic. Clean and degrease first, sand glossy spots lightly, then apply thin coats. Finish with a clear protective coat if you want easier cleanup next time. Dispose of rags, runoff, and empty containers properly, and wash your hands afterward. It’s a bit of elbow grease, but you can usually get an urban trash can looking decent again in an afternoon.