I solved my (legendary to those who know me) problem in a rather unconventional way.
I got a bucket, poured a small amount of bleach into it, and added warm water. Then I sat on the toilet and read a book for at least fifteen minutes, every day. Don’t even think of doing this if you have broken or irritated skin. In fact, you probably shouldn’t do this at all.
I tossed all of my old socks and most of my shoes. I ripped the insoles out of the shoes I kept, dumped an exhorbitant amount of anti-fungal foot powder into them, then replaced the insoles.
My shoes and socks came off at every single possible moment. Socks are doused with foot powder the moment they come out of the laundry. I have even toyed with the idea of pouring foot powder into the dryer, but I haven’t tried it yet.
And–here’s the hardest part to fathom–I never wash my feet. I don’t know why this works, but I swear it does. My guess is that there’s so much anti-fungal foot powder and oil jammed into the pores of my skin that my feet simply can’t sweat anymore. By now, they’re practically waterproof in the shower.
Anyway, the bleach treatment lasted a month, and I still do the foot powder. No problems at all for almost two years now, which is judged to be miraculous by my friends and family.
Okay, my favorite shoe destinker:
You need a large industrial-sized can of fabric refresher–although I love Febreze, I use another kind that is in a can for this. (I’ve tossed the last can, but I think it’s by a laundry detergent company…will post if I remember.) I think it’s better because of the propellant–no wimpy hand-sprayed fragrance here!
First, if you can take the foot-shaped pad out, do so, and clean them. I soak mine in hot, soapy water, and then scrub them with a brush and use a thingy to sort of squeegee dirt from them. They are disgusting, frankly, but if they get too bad I can buy replacements. Leave those aside to dry while you…
Spray the inside of the shoes heavily. In fact, stick the little spray thingy inside the shoe and FOG those suckers. Use a LOT.
Quick, before the fog begins to roll across the room, stuff a couple of paper towels into the opening of the shoe, so that the fumes are trapped in there. Set them aside for at least 4 hours; overnight is better.
Take out the paper towels and toss the shoes in the dryer for 30 minutes or so. When they come out, they should smell fresh as daisies. For a while, at least.
I do this with my nastiest shoes ever, and it works like magic. Temporary magic, but still.
I had this problem when I started my first job out of college. Horrendous stink. It turns out that the reason it started at that time was: dress code. My new job required that I wear dress shoes, so naturally I bought some dress socks to go with them. The socks were too thin. They couldn’t absorb enough sweat, so my feet (and my shoes) picked up a mighty stench. The solution was black sweat socks. Cured me instantly. In a pinch, two layers of dress socks minimizes the problem.
Sofa King of the Waterproof Feet…I like it. 
Whatever was afflicting your tootsies, I’m guessing you done kilt it, Sofa King. But don’t put your foot powder in the dryer, okay? I can’t imagine the results being worth the trauma.
Thanks, everyone!
My XBIL swore that daily zinc suplements kept his feet at bay.
I do wear cotton socks, on those occasions that I must wear socks at all. (I’m trying, I’m trying!)
I’m sure the ventilation aspect is a problem, because I wade so many puddles this time of year that my shoes have to be waterproof. Basically, I spend 3-4 hours alternating between hiking in the cold and wet and sitting in the heated car, every single day.
It seems to be better than it was–perhaps the essence of wisdom offered here is having an effect.