I'm a Former SpaceX Engineer Destroying Shoe Odor with NASA-Tested Tech. #AMA

For a cheaper alternative just stop wearing shoes so much. At least take them off when you are indoors at home.

Coming from Europe and visiting US homes I was always surprised that people wear shoes indoors. My hosts would always protest that I didn't need to take my shoes off. In my family (southern England) shoes were always taken off at the door and this is usual where I live now (Norway).