Info from Today.com
Sprinkle baking soda in sneakers. Allow to sit overnight. Shake out baking soda before wearing shoes.
Smelly towels are often caused by detergent build-up. To freshen smelly towels, wash in hot water and one cup vinegar, then again in hot water and ½ cup baking soda. Reichert recommends not using laundry detergent during this process. Detergent stays in the towels, even after rinsing, and can hold the smells.
What not to clean with baking soda and/or vinegar:
Do not use vinegar on anything shiny as it is an acid, and, over time, can remove the shine.
Do not use vinegar on sealed countertops such as granite or marble. It won't hurt the stone but it will slowly remove the shine.
Don't use baking soda as an abrasive scrub on surfaces that scratch easily.
When in doubt, first test products on a small, inconspicuous part of the item to be cleaned.