Even with a trash bag in your trash can liquid and food particles can escape and cause nasty things to grow and create bacteria that not only smell nasty but produce things we don't want to touch or breath . Every time I change the trash bag out, I spray my normal all-purpose cleaner on the inside and outside. It has disinfecting properties to it. I let it air dry before putting in a new bag.
But every so often (about once a month to every 6 weeks), I wash and do a more thorough cleaning of the trash can. This will not only work for your kitchen trash can but all the other trash cans in your home. When cleaning the trash cans I bring to the curb, I just do this process but outside with the hose.
We have a shower that as detachable sprayer/hose so that it isn't fixed position. I use the sprayer on it to rinse off with hot water. I fill it up about 1/3 of the way with hot water and liquid dish soap and let it soak for about 10 to 15 minutes. Then take a scrub brush to it and give it a good cleaning. Making sure I get all the corners, around ridges and the lip of the trash can.
If you don't have a shower you can use, then use your tub and a pitcher to fill with water and pour over your trash can. You can also use the outside hose even though it isn't hot water working with all purpose cleaner and soap will get it clean.
After you have washed it in the shower (or tub or outside), let air dry or pat dry. Then spray with an disinfecting all-purpose cleaner and either dry with a towel or allow to air dry. You can also leave it to dry in the sun and the sun will help in destroying any other lingering bacteria.