During rainy season, footwear is often wet and due to moisture in air and cloudy weather, it takes time to dry. And it ends up with odour which is very unpleasant in nature.
To deodorize sneakers and tennis shoes, an easy solutions to eliminate odor is to wash them in a laundry machine with detergent, cold water and no spin cycle. Before washing, separate the shoe laces and insoles from the shoes.
It is really important to turn off the spin cycle or the shoes will be destroyed. (cough, cough)
After washing, you'll need to dry them. Leave them in the sun for a couple of days, on a cloths line hanging from the tongue. If you live in a humid area where two days isn't enough, consider investing in a shoe dryer.
Various sources on the internet warn to avoid using bleach with the shoes in the washing machine. I personally always use a little bit of bleach just to make sure the shoes are perfectly disinfected.
Please note, don't do this plan with leather shoes or sandals.
Edit: Yesterday, I dried my shoes with a hair dryer. I turned the heat off, and stuck it in on high blow. It was mostly dry in a few minutes.
Refer to my answer here: https://lifehacks.stackexchange.com/a/14156/17827
Sodium Bicarbonate really is a wonderful substance, it helps with a lot of things, lessening effects of bad odor is just one of them. Do read my other answer.
What would be the easiest way for you to be able to dry your footwear? I would suggest an oven you heat up for less than a minute empty. Turn it off. Then put your shoes in it on a tray that is room temperature. But if you do that wrong, you will have burnt shoes. :( But an oven that is already heated just a little bit will dry anything out pretty well. Also, you can put shoes in a regular dryer, or in the sun coming through a window. Anything to get the temperature up just a little bit so the water evaporates faster.
Also, and this may not apply to you at all, but most smell from shoes come from bacteria that grow naturally on your feet. That bacteria will build up throughout the day in your socks, then be washed away when you wash your socks. If you are NOT wearing socks, you will have LOTS of bacteria in your shoes, and they will always stink, wet or not. The only way to get rid of it is to wash your shoes regularly, which is not good for them.