My understanding is that foot odour is generally bacteria related.
I am an ex nurse so have been germ phobic and a compulsive hand washer for years!
Some helpful hints for you.
When you travel take a pair of clean thongs or some slide slippers. To be used ONLY on clean feet. When you have showered don't walk around bare foot until you are ready to get dressed for work. Dry your feet thoroughly after you shower and slip on your slides or thongs straight away, so you don't pick up bacteria from the other millions of people who walk through hotel rooms.
Do the same at home. ( Let's be reasonable, who has time to wash their floor every day! And we track dirt in on our shoes from outside regularly.)
Try using a tea tree soap on your feet. It's a great anti bacterial. And wipe the inside of your shoes out when you finish work with an anti bacterial wet wipe and allow them to dry overnight.
You can also rub tea tree oil over your feet after a shower.
I have always done this and have never experienced foot odour.
Wash your stockings in a lingerie bag in the machine and use canasten rinse in your final cycle.
Obsessive/compulsive? A little!
Hope it helps.
Cheers.