Place a dryer sheet in each boot to get rid of the smell. Leave them there for at least eight to 10 hours. Put the sheets back in after wearing the boots if they still stink.
Sprinkle a generous amount of baking soda inside the boots. Before wearing them again, shake the baking soda out.
Place an odor-absorbing insole inside the boots. Several commericial products are sold for this purpose and some must be cut to fit different shoe sizes.
Adopt habits to prevent your boots from becoming stinky again. Sprinkle a little bit of baking soda inside the boots between uses. Also, loosen the laces and open the boots up to allow for good air flow when not in use. Don't wear your boots for more than one day in a row to give them time to air out. Clean your feet with deodorizing soaps every day, including between your toes. Dry your feet completely before wearing your boots. Wear thick cotton or wool socks, which absorb sweat better than synthetic fibers.