Fill a spray bottle with pure white vinegar.
Remove all shoes from the rack, and spray the vinegar over the entire rack. The vinegar is not only a disinfectant, but also a natural deodorizer that removes the foul smell without using the harsh chemicals found in many commercial deodorizers and disinfectants.
Let the shoe rack absorb the vinegar for about 10 minutes, then wipe down the shoe rack with a damp cloth.
Repeat monthly or as needed when foul odor becomes present. The vinegar can also be sprayed into the insoles of shoes to kill odor.