The smell of a dirty garbage can is notorious for its gag-inducing effects. The caked on juices of old chicken and rotten eggshells is enough to curl anyone's back hair.
You may have tried rinsing it out with your garden hose, but that only removes loose bits of trash - not the syrupy bacteria-ridden residue. Removing the smell requires some detergent and a lot more water pressure.
A rotating scrub brush attachment is recommended for projects like this. The spinning brush will do the work for you, saving you time and energy.
The power of your pressure washer spins the inner brushes of the attachment making the removal of build-up in your trash can almost effortless.