Empty your trash can on pickup day and it still smells. That's because the smell was never coming from the bag. It comes from the thin layer of liquid, food scraps, and residue that leaks out of bags and bakes onto the floor and walls of the cart.
In Central Florida, a closed plastic cart sitting in the sun can get far hotter than the air around it. Heat and moisture are exactly what bacteria need to multiply, and that's what turns a little residue into a sour, rotting smell within days. Flies find it next, and where flies lay eggs, maggots follow.
A garden hose rinse moves some of the mess around, but it doesn't remove the film stuck to the plastic, and it usually leaves the dirty water on your driveway. Getting rid of the smell means removing that residue with hot, high-pressure water, then sanitizing the surface so bacteria don't come right back.
A few habits help between cleans: double-bag anything wet, keep the lid closed, and park the cart in the shade when you can. But in an Orlando summer, a regular professional clean, monthly for most homes, is what keeps the smell from coming back.