Empty the Garbage
The first thing you will need to do is empty the garbage can as well as possible. This will facilitate rest of the cleaning process. It must be noted that the best time to clean your garbage can is during the daytime, as the sunshine is going to be helpful to you.
Fill the garbage can halfway with hot water. Allow this to sit for a couple of minutes.
Put on your rubber gloves and add approximately 1/4 to 1/2 cup of bleach or ammonia to the water. Allow this to sit for 30 minutes to 2-3 hours depending on how dirty and smelly the garbage is.
Note: DO NOT add bleach and ammonia together as the mixture produces toxic fumes.
Once you have allowed the solution to work its magic, use your brush to scrub the can thoroughly. Be sure to clean and scrub the entire inside of the garbage can. If you find it easier, you may use one of your old clothes rather than the scrub brush.
Pour out the bleach or ammonia solution down a sink or into a toilet. This will be harder to do with larger cans.
Rinse and Dry
Rinse out the garbage can once again with hot water. It should now be completely clean. Allow the can to sit outside in the sunlight. The sun will kill off any remaining bacteria and also dry the can.
If you can't use the sun to dry the can, use paper towel or a clean rag until completely dry.